Pipetting Device, Pipette Tip Coupler, and Pipette Tip: Devices and Methods

ABSTRACT

Pipette tip couplers, pipette tips, coupler and tip combinations, and methods for coupling and decoupling a pipette tip to or from, respectively, a pipette tip coupler mounted on a pipette device, are disclosed. The pipette tip couplers include an elastomeric element and an annular ring shaped raceway. When the pipette tip is mounted on the pipette tip coupler, the annular ring shaped raceway abuts a first portion of the interior surface of the circumscribing sidewall of the pipette tip, and the elastomeric element abuts a second portion of the interior surface of the circumscribing sidewall of the pipette tip.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 USC sections 119(e), 120, and 121, this application is acontinuation of and claims the benefit of priority from co-pending U.S.patent application Ser. No. 16/842,441 entitled “Pipetting Device,Pipette Tip Coupler, and Pipette Tip: Devices and Methods” filed on Apr.7, 2020, which is a divisional of and claims the benefit of priorityfrom U.S. Pat. No. 11,117,125 entitled “Pipetting Device, Pipette TipCoupler, and Pipette Tip: Devices and Methods” issued on Sep. 14, 2021,which is a continuation of and claims the benefit of priority from U.S.Pat. No. 10,272,425 entitled “Pipetting Device, Pipette Tip Coupler, andPipette Tip: Devices and Methods” issued on Apr. 30, 2019, which claimsthe benefit of priority from two (2) U.S. provisional patentapplications, No. 62/350,291 filed on Jun. 15, 2016 and No. 62/350,302filed on Jun. 15, 2016, all of which are incorporated herein byreference.

FIELD

This disclosure pertains generally to pipetting devices, and moreparticularly to pipette tip couplers, disposable pipette tips, tip andcoupler combinations, and coupling and decoupling methods of at leastone disposable pipette tip to or from at least one pipette tip couplercarried by a pipette device.

BACKGROUND

Pipette devices are used in a multitude of industries for the transferof liquids to conduct experimental analysis. As such, to provide controlwithin the experiments being performed, disposable tips are used andintended for one-time use. Disposable tips are employed with both manualpipette devices and automated pipette devices having a large number ofpipette units arranged in a row or in a matrix for aspirating samplessimultaneously from a large number of vessels and dispensing themelsewhere.

Disposable pipette tips have been constructed historically to interfaceto either a conical or stepped coupling stud. In the cases where aconical coupling stud is used, the disposable tip is constructed in amanner that it must be pre-stressed onto the coupling stud to provide anair tight seal. Due to the tolerances of the two interfacing components,the distance to the end of the tip that comes in contact with liquid isnot well controlled. In addition, high press forces are required topre-stress the tip to create the air tight seal. As a result,microfissures may be formed in the pipette tip which are a cause ofleakage. Moreover, the high press forces upon placement of the pipettetip have the disadvantage that for the release of the pipette tipcorrespondingly high forces have to be applied.

The assignee of the present application, HAMILTON Company, teaches inU.S. Pat. No. 7,033,543, issued Apr. 25, 2006, a stepped coupling studin conjunction with an O-ring that provides a solution for reducing thehigh press force required to create an air tight seal as well asproviding well defined axial positioning of the end of the tip thatcomes in contact with liquid. As the O-ring is compressed, it providesaxially directed force to not only provide the air-tight seal, but alsoto engage the axial coupling feature on the coupling stud with thecounter axial coupling feature on the tip.

Nevertheless, current systems utilizing a stepped coupling stud and asolitary O-ring configuration are problematic when the O-ring becomescompromised because the result is an impairment in the air-tight sealand the performance of the pipette device.

Additionally, the compression of the O-ring results in the deformationof the O ring that in turn provides the axially directed force andair-tight seal against the working surface of the pipette tip. Counterto this operation, when the compression of the O-ring is removed, theO-ring must disengage from the working surface of the pipette tip toallow the pipette tip to be removed from the coupling stud and thepipette device for disposal. If the O-ring does not fully decompress,some residual force will remain resulting in keeping the tip engaged tothe coupling stud and thus requiring an automated external axialcounterforce to remove the tip for disposal.

Moreover, as the size of the holes to and/or from which liquid istransferred decreases, the need for precision positioning of all of thetips in a controlled manner increases in order to allow successfultargeting.

Hence, there is a need to ameliorate or overcome one or more of thesignificant shortcomings delineated hereinabove.

SUMMARY

Accordingly, and in one aspect, an embodiment of the present disclosureameliorates or overcomes one or more of the shortcomings of the knownprior art by providing a pipette tip coupler and disposable pipette tipcombination that comprises a plurality of circumferentially disposedelements or segments engaging a circumferential interior working surfacedefining a first working surface of an interior circumscribing surfaceof a sidewall of the pipette tip in an area superior to a proximallyfacing axial stop surface of the pipette tip for providing a resultantpre-stress force that pre-stresses the pipette tip axially upwardcausing a distal elastomeric element of the coupler to be pre-stressedagainst a second working surface of the pipette tip forming a sealconfiguration that eliminates the seal deterioration or failure of theknown prior art.

In addition, and in one aspect, the distal elastomeric element, whencompressed against the second working surface, provides a counter axialforce to the plurality of elements or segments wherein at least onebenefit of this counter axial force is that additional force is appliedto the first working surface by the plurality of individual elements orsegments when the plurality of individual elements or segments are in aradially and axially interfacing state for providing a stronger distalseal.

A further benefit of the counter axial force is that when the pluralityof individual elements or segments are disengaged to a radially andaxially retracted state, the counter axial force of the distalelastomeric element defines a counter axially directed disengaging forcethat aids in the removal of the pipette tip from the pipette tip couplerfor disposal.

In another aspect, an embodiment of the present disclosure provides apipette tip coupler and disposable pipette tip combination, the couplercomprising a plurality of circumferentially disposed elements orsegments and a distal elastomeric element in the form of, but notlimited to, an O-ring and the pipette tip comprising dual complementalworking surfaces in the pipette tip to provide a resultant axial forceachieved from an engagement of the plurality of elements or segments andthe distal elastomeric element with the dual complemental workingsurfaces for pre-stressing the disposable pipette tip into an axialcoupling position that is provided by a distally facing axial stopsurface of the pipette tip coupler and a proximally facing complimentarycounter axial stop surface of the disposable pipette tip such that aperpendicular datum is established to a longitudinal axis of a channelof a pipette device carrying the pipette tip coupler and disposablepipette tip combination that provides for tip straightness andcontrolled concentricity.

One benefit of the resultant axial force coupling position over theknown prior art is the establishment of this perpendicular datum thatprovides for tip straightness and controlled concentricity.Concentricity becomes worse as an angle defined herein as “ø” between atransverse axis and the longitudinal axis perpendicular to thetransverse axis is allowed to increase. Thus, controlled concentricitybecomes especially important in a multi-channel system and whentargeting multiple wells. Accordingly, the pipette tip coupler anddisposable tip combination provides tighter concentricity to allow fortighter precision of all the tips in a controlled manner allowingsuccessful targeting of multiple wells and/or smaller holes to and/orfrom which liquid is transferred.

In yet another aspect, an embodiment of the present disclosure providesa pipette tip coupler and disposable pipette tip combination, thecoupler comprising a plurality of circumferentially disposed elements orsegments and a distal elastomeric element in the form of, but notlimited to, an O-ring and the pipette tip comprising dual complementalworking surfaces in the pipette tip to provide precise control of anaxial coupled position defined as an axial distance from a distallyfacing axial stop surface of the pipette tip coupler to the end of thepipette tip that contacts liquid when the pipette tip coupler anddisposable pipette tip are in a coupled configuration. This, combinedwith tip straightness, allows for a pipette device carrying the pipettetip coupler and disposable tip combination to target smaller holes.Additionally, smaller volumes of liquid can be transferred resultingfrom the known fixed distance of the disposable pipette tip allowing fora controlled touch of the pipette tip/liquid to a working surface ontoor from which liquid is to be transferred.

In a further aspect, an embodiment of the present disclosure provides apipette tip coupler and disposable pipette tip combination comprising anangled squeeze mechanism, such as an annular wedge or squeeze ring, thatdirects the motion of the plurality of individual elements into contactwith the first working surface of the pipette tip. The result is moreaxial force to pre-stress the pipette tip into the axial couplingposition.

In yet a further aspect, an embodiment of the present disclosureprovides a pipette tip coupler device for coupling a pipette tip to apipette device, the pipette tip coupler device comprising: a pipette tipcoupler body having an upper seating surface and a distally facing axialstop surface that is complementary to a proximally facing axial stopsurface of an axially stepped shoulder of an interior circumscribingsurface of a sidewall of a pipette tip; a distal stem portion distallyextending from a distal surface of the pipette tip coupler body along acentral longitudinal axis of the pipette tip coupler body andterminating to a distal end; a distal elastomeric element circumscribingthe distal stem portion, the distal elastomeric element comprising arelaxed state, and a compressed state configured for sealing andabutting the distal elastomeric element with a circumferential radiallyinwardly angled and distally extending distal sealing surface of theinterior circumscribing surface of the sidewall of the pipette tiplocated in an area inferior to the axially stepped shoulder of thepipette tip; and a plurality of individual elements or segmentscircumferentially spaced apart and mounted on the upper seating surfaceof the pipette tip coupler body and configured to extend betweencircumferentially spaced apart radially retracted positions andcircumferentially spaced apart radially advanced positions configuredfor providing an abutment of the plurality of individual elements orsegments with a first interior working surface of the interiorcircumscribing surface of the sidewall of the pipette tip in an areasuperior to the axially stepped shoulder of the pipette tip while thedistal elastomeric element is concurrently in the compressed state andthe upwardly facing axial stop surface of the pipette tip is in abutmentwith the downwardly facing axial stop surface of the pipette tip couplerbody to define an axial coupling position of the pipette tip on thepipette tip coupler device.

Further aspects of the embodiments of the present disclosure will becomeapparent from the detailed description provided below, when takentogether with the attached drawings and claims. It should be understood,however, that numerous modifications and adaptations may be resorted towithout departing from the scope and fair meaning of the claims as setforth below following the detailed description of preferred embodimentsof the present disclosure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe disclosure, will be more fully understood by reference to thefollowing drawings that are for illustrative purposes only, and are notintended to limit the scope of the present disclosure. Also, it isappreciable that the drawings are not necessarily in scale as somecomponents may be shown to be enlarged or to be out of proportionrelative to the size in actual implementation in order to more clearlyillustrate one or more concepts of the present disclosure. In thedrawings:

FIG. 1 is a perspective view of an example embodiment of an airdisplacement pipette device assembly of an automated liquid handlingsystem.

FIG. 2 is a longitudinal sectional, side elevational view of an exampleembodiment of the pipette device assembly.

FIG. 3 is a fragmentary longitudinal sectional, side elevational view ofan example embodiment of the pipette device assembly comprising apipette device operatively coupled to an example embodiment of a pipettetip coupler device that is operatively coupled to an example embodimentof a disposable pipette tip.

FIG. 4 is a side elevational view of an example embodiment of thepipette device assembly.

FIG. 5 is a partial exploded parts perspective view of an exampleembodiment of the pipette device assembly detailing parts of an exampleembodiment of the pipette tip coupler device.

FIG. 6 is a side elevational view of an example embodiment of thepipette tip coupler device.

FIG. 7 is a top and side perspective view of an example embodiment of apipette tip coupler body of an example embodiment of the pipette tipcoupler device.

FIG. 8 is a top and side perspective view of an example embodiment of adistal elastomeric element or O-ring of an example embodiment of thepipette tip coupler device.

FIG. 9 is a top and side perspective view of a crowned shaped ballraceway of an example embodiment of the pipette tip coupler device, theraceway comprising a plurality of circumferentially spaced apart guidesockets each configured to receive a spherical ball or discrete couplingelement or segment.

FIG. 10 is a top and side perspective view of the crowned shaped ballraceway with a spherical ball or discrete coupling element or segmentreceived within each of the plurality of circumferentially spaced apartguide sockets.

FIG. 11 is a fragmented and cutaway, longitudinal sectional, sideelevational view of a portion of the crowned shaped ball raceway and asegment or ball received within the raceway.

FIG. 12 is a top and side perspective view of the annular wedge orsqueeze ring of an example embodiment of the pipette tip coupler device.

FIG. 13 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette device operatively coupled tothe example embodiment of the pipette tip coupler device.

FIG. 14 is a fragmentary, partially sectional, side elevational view ofan example embodiment of the pipette device operatively coupled to anexample embodiments of the pipette tip coupler device and tip.

FIG. 15 is a side elevational view of an example embodiment of thedisposable pipette tip illustrated in a supported position.

FIG. 16 is a fragmentary, longitudinal sectional, side elevational viewdetailing the interior of an example embodiment of the disposablepipette tip.

FIG. 17 is an upper detail fragmentary, longitudinal sectional, sideelevational view detailing the upper interior of an example embodimentof the disposable pipette tip.

FIG. 18 is a diagrammatical block diagram view of an example embodimentof an automated pipetting workstation or system.

FIG. 19 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette device supporting an exampleembodiment of the pipette tip coupler device over an example embodimentof the disposable pipette tip.

FIG. 20 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device positionedover and into an example embodiment of the disposable pipette tip forbringing the plurality of circumferentially spaced apart segments orballs into contact with the proximal open end of the pipette tip.

FIG. 21 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device moved into anexample embodiment of the disposable pipette tip for contacting thedistal O-ring against the tip sealing seat or surface such that a gap ismaintained between the annular shoulder seat or stop surface of thepipette tip and the stop shoulder surface of the stop disk with theplurality of circumferentially spaced apart segments or balls retractingby contacting the interior surface of the pipette tip and being forcedinwardly.

FIG. 22 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device moved intothe tip a further amount with the annular wedge initially squeezing theelastomeric element or O-ring and the tip being lifted up for defining afirst extended or lift state with the distal elastomeric element orO-ring in an initially compressed and seated state.

FIG. 23 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device moved a finaldistance into the tip with the tip being lifted up to its final seatedstate to engage the coupler by the method of moving the annular wedgeinto its final position thereby defining a final state of coupling withthe distal elastomeric element or O-ring in a final compressed andseated sealing state.

FIG. 24 is a longitudinal sectional, side elevational, fragmenteddetailed view of one of the plurality of segments or balls in the finalextended or lift state as is illustrated in FIG. 23.

FIG. 25 is a longitudinal sectional, side elevational, fragmenteddetailed view of the distal elastomeric element or O-ring in a finalcompressed state against the tip sealing seat or surface as isillustrated in FIG. 23.

FIG. 26 is a fragmentary, longitudinal sectional, side elevational, viewof an initial coupling state of an example embodiment of the pipette tipcoupler device with the disposable pipette tip with an illustration ofassociated forces.

FIG. 27 is a fragmentary, longitudinal sectional, side elevational,detailed view of the initiation of coupling of one of a plurality ofsegments or balls of an example embodiment of the pipette tip couplerdevice with a groove of an example embodiment of the disposable pipettetip with an illustration of associated forces.

FIG. 28 is a fragmentary, longitudinal sectional, side elevational,detailed view of an example embodiment of the coupler and tipcombination in the completed coupling state as illustrated in FIG. 23and further illustrating associated forces.

FIG. 29 is a fragmentary, longitudinal sectional, side elevational viewof a misaligned coupling between an example embodiment of a pipette tipcoupler device and an example embodiment of a disposable pipette tip.

FIG. 30 is a fragmented and cutaway, longitudinal sectional, sideelevational view of an example embodiment of an air displacement pipettedevice operatively coupled to an example embodiment of a pipette tipcoupler device that is illustrated in the misaligned coupling state withan example embodiment of a disposable pipette tip.

FIG. 31 is a fragmented and cutaway, longitudinal sectional, sideelevational view of an example embodiment of the air displacementpipette device supporting in axial alignment an example embodiment ofthe pipette tip coupler device that, in turn, is coupled in axialalignment to the disposable pipette tip wherein the tip is illustratedwith a small liquid volume interposed between its distal end of the tipand a working surface and with dimensioning lines illustrated andidentified.

FIG. 32 is a longitudinal side elevational view of an example embodimentof the pipette device assembly illustrating a circuit board thatprocesses a signal received from a Liquid Level Detection (LLD) circuitcontact connected between the circuit board and the annular wedge orsqueeze ring that selectively contacts a plurality of conductivesegments or balls coupling with a conductive disposable pipette tipwherein the distal end of the tip is in contact with the liquid.

FIG. 33 is a top and side perspective view of an alternative exampleembodiment of a ball raceway for use with the pipette device assemblyillustrated in FIG. 5.

FIG. 34 is a partial exploded parts perspective view of a plurality ofsegments or balls and the alternative example embodiment of the ballraceway mounted on a coupler body.

FIG. 35 is a top and side perspective view of the plurality of segmentsor balls captured by the alternative example embodiment of the ballraceway mounted on the coupler body.

FIG. 36 is a fragmented and cutaway, longitudinal sectional, sideelevational view of one of the plurality of segments or balls receivedand captured within the alternative example embodiment of the ballraceway.

FIG. 37 is a top and side perspective view of a ball raceway and apipette tip coupler body of a second example embodiment of a pipette tipcoupler device for use with the pipette device assembly illustrated inFIG. 5.

FIG. 38 is a partial exploded parts perspective view illustrating aspacer, a magnetic ring, and the ball raceway mounted on pipette tipcoupler body of the second example embodiment of a pipette tip couplerdevice.

FIG. 39 is a partial exploded parts perspective view illustratingsegments or balls, a top lid ring, and the ball raceway mounted onpipette tip coupler body of the second example embodiment of a pipettetip coupler device.

FIG. 40 is a fragmented and cutaway, longitudinal sectional, sideelevational view of one of the plurality of segments or balls receivedand captured within the ball raceway of the second example embodiment ofthe pipette tip coupler device.

FIG. 41 is a bottom and side perspective view of a third exampleembodiment of a pipette tip coupler device comprising a pipette tipcoupler body supporting a distal sealing element and a ball raceway witha snap ring securing a plurality of segments or balls therein.

FIG. 42 is a longitudinal sectional, side elevational view of the thirdexample embodiment of the pipette tip coupler device utilizing theannular wedge or squeeze ring that is illustrated in FIG. 12.

FIG. 43 is a fragmentary, longitudinal sectional, side elevational viewof the third example embodiment of the pipette tip coupler deviceillustrating the contact between the annular wedge or squeeze ringillustrated in FIG. 12 and one of the plurality of segments or balls andfurther illustrating the snap ring securing one of the plurality ofsegments or balls.

FIG. 44 is a partial exploded parts perspective view illustrating thepipette tip coupler body and the ball raceway of the third exampleembodiment of the pipette tip coupler device.

FIG. 45 is a partial exploded parts perspective view illustrating aspacer, a magnetic ring, and the ball raceway mounted the pipette tipcoupler body of the third example embodiment of the pipette tip couplerdevice.

FIG. 46 is a partial exploded parts perspective view of segments orballs disposed proximate front entry openings of the ball raceway of thethird example embodiment of the pipette tip coupler device.

FIG. 47 is a partial exploded parts perspective view of the snap ringdisposed axially above the ball raceway of the third example embodimentof the pipette tip coupler device.

FIG. 48 is a fragmented and cutaway, longitudinal sectional, sideelevational view of a portion of the ball raceway of the third exampleembodiment of the pipette tip coupler device with one of the pluralityof segments or balls received and captured therein.

FIG. 49 is a bottom and side perspective view of another or secondembodiment of an annular wedge or squeeze ring comprisingcircumferentially spaced apart concave faces or concavities.

FIG. 50 is a longitudinal sectional, side elevational view of the thirdexample embodiment of the pipette tip coupler device utilizing thesecond embodiment of the annular wedge or squeeze ring illustrated inFIG. 49 with the curvature of each of the circumferentially spaced apartconcave faces or concavities being complemental in shape to the exteriorarcuate shape of each of the plurality of segments or balls forcomplemental surface abutment therebetween as illustrated.

FIG. 51 is a longitudinal sectional, side elevational view of a fourthexample embodiment of a pipette tip coupler device comprising analternative ball raceway having a machined ball retention configurationsecuring a plurality of segments or balls therein.

FIG. 52 is a longitudinal sectional, side elevational view detailing themachined ball retention configuration of the ball raceway of the fourthexample embodiment of the pipette tip coupler device.

FIG. 53 is a partial exploded parts perspective view of segments orballs disposed proximate rear openings of the ball raceway of the fourthexample embodiment of the pipette tip coupler device.

FIG. 54 is a partial exploded parts perspective view illustrating apipette tip coupler body and the ball raceway of the fourth exampleembodiment of the pipette tip coupler device.

FIG. 55 is a partial exploded parts perspective view illustrating anannular spacer or ring of the fourth example embodiment of the pipettetip coupler device and the mounting of the ball raceway on the pipettetip coupler body of the fourth example embodiment of the pipette tipcoupler device.

FIG. 56 is a fragmented and cutaway, longitudinal sectional, sideelevational view of a portion of the ball raceway of the fourth exampleembodiment of the pipette tip coupler device with one of the pluralityof segments or balls received and captured therein by the machined ballretention configuration.

FIG. 57 is a partial exploded parts perspective view detailing parts ofa fifth example embodiment of a pipette tip coupler device interposedbetween the disposable pipette tip and the pipette device of the airdisplacement pipette device assembly.

FIG. 58 is a top and side perspective view of an example embodiment ofthe pipette tip coupler device.

FIG. 59 is a top and side perspective view of an example embodiment of apipette tip coupler body of the fifth example embodiment of the pipettetip coupler device.

FIG. 60 is a top and side perspective view of an example embodiment of adistal elastomeric element or O-ring of the fifth example embodiment ofthe pipette tip coupler device.

FIG. 61 is an exploded parts perspective view of a segmented couplingsystem of the fifth example embodiment of the pipette tip coupler devicecomprising a plurality of segments or individual coupling elements and aretaining ring.

FIG. 62 is a top, back, and side perspective view of a discrete couplingelement or segment of the segmented coupling system of an exampleembodiment of the pipette tip coupler device.

FIG. 63 is a top and front perspective view of the discrete couplingelement or segment illustrated in FIG. 62.

FIG. 64 is a top and side perspective view of the annular wedge of anexample embodiment of the pipette tip coupler device.

FIG. 65 is a longitudinal sectional, side elevational, fragmented viewof an example embodiment of the pipette device supporting an exampleembodiment of the pipette tip coupler device over an example embodimentof the disposable pipette tip.

FIG. 66 is a longitudinal sectional, side elevational, fragmented viewof the fifth example embodiment of the pipette tip coupler devicepositioned over and moved into an example embodiment of the disposablepipette tip for bringing the distal O-ring into contact with the tipsealing seat or surface while maintaining the plurality of discretecoupling elements or segments in a radially unextended state and beforethe shoulder seat of the pipette tip and the stop shoulder surface ofthe stop disk are mated such that a gap is maintained between theannular shoulder seat of the pipette tip and the stop shoulder surfaceof the stop disk.

FIG. 67 is a longitudinal sectional, side elevational, fragmented viewof the fifth example embodiment of the pipette tip coupler device movedinto the tip a further amount with the tip being lifted while pushingdown on the annular wedge squeeze ring for radially extending thesegmented coupler into the groove of the tip.

FIG. 68 is a longitudinal sectional, side elevational, fragmenteddetailed view of one of a plurality of segments of the segmented couplerbeing extended into the groove of the tip as is illustrated in FIG. 67.

FIG. 69 is a longitudinal sectional, side elevational, fragmenteddetailed view of the distal O-ring in a compressed state against the tipsealing seat or surface as is illustrated in FIG. 67.

FIG. 70 is a longitudinal sectional, side elevational, fragmented viewof the fifth example embodiment of the pipette tip coupler device movedinto the disposable pipette tip to a final amount with the tip beinglifted with a force pushing down on the annular wedge or squeeze ringfor defining a final state of coupling of the fifth example embodimentof the pipette tip coupler device with the disposable pipette tip.

FIG. 71 is a longitudinal sectional, side elevational, fragmenteddetailed view of one of a plurality of segments of the segmented couplerbeing fully extended into the groove of the tip as is illustrated inFIG. 70.

FIG. 72 is a longitudinal sectional, side elevational, fragmenteddetailed view of the distal O-ring in a final compressed state againstthe tip sealing seat or surface as is illustrated in FIG. 70.

FIG. 73 is a fragmentary, longitudinal sectional, side elevational, viewof an initial coupling state of the fifth example embodiment of thepipette tip coupler device with the disposable pipette tip with anillustration of associated forces.

FIG. 74 is a fragmentary, longitudinal sectional, side elevational,detailed view of the initiation of coupling of one of a plurality ofarcuate segments of the fifth example embodiment of the pipette tipcoupler device with the groove of an example embodiment of thedisposable pipette tip with an illustration of associated forces.

FIG. 75 is a fragmentary, longitudinal sectional, side elevational,detailed view of the completed combination coupling state of the fifthexample embodiment of the pipette tip coupler device and disposablepipette tip with an illustration of associated forces.

FIG. 76 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the disposable pipette tip comprising analternative sealing seat surface angle of substantially ninety degreesrelative to the central longitudinal axis of the pipette tip.

FIG. 77 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device positionedover an example embodiment of the disposable pipette tip comprising thealternative sealing seat surface angle of substantially ninety degrees.

FIG. 78 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device positioned inthe disposable pipette tip comprising the alternative sealing seatsurface angle of substantially ninety degrees wherein the tip is liftedup to its final seated state and the annular wedge moved into its finalposition for defining a final coupling state with the distal elastomericelement in a final compressed and seated sealing state against thesealing seat surface having the alternative sealing seat surface angleof substantially ninety degrees.

FIG. 79 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the distal elastomeric element in the final compressedstate against the sealing seat surface having the alternative sealingseat surface angle of substantially ninety degrees as is illustrated inFIG. 78.

FIG. 80 is a fragmentary, longitudinal sectional, side elevational viewof the upper interior of an example embodiment of the disposable pipettetip comprising another alternative sealing seat surface in the form of acircumferential radially concave sealing seat surface.

FIG. 81 is a fragmentary, longitudinal sectional, side elevationaldetailed view of an example embodiment of the disposable pipette tipillustrating detail of the circumferential radially concave sealing seatsurface illustrated in FIG. 80.

FIG. 82 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the disposable pipette tip illustratingdetail of a further alternative sealing seat surface in the form of acircumferential radially convex sealing seat surface.

FIG. 83 is a fragmentary, longitudinal sectional, side elevationaldetailed view of an example embodiment of the disposable pipette tipillustrating detail of the circumferential radially convex sealing seatsurface illustrated in FIG. 82.

FIG. 84 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the disposable pipette tip illustrating ayet further alternative sealing seat surface in the form of acircumferential upward facing tooth edge sealing seat surface.

FIG. 85 is a fragmentary, longitudinal sectional, side elevationaldetailed view of an example embodiment of the disposable pipette tipillustrating detail of the circumferential upward facing tooth edgesealing seat surface illustrated in FIG. 84.

FIG. 86 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device positionedover the example embodiment of the disposable pipette tip comprising analternative circumferential annular tip groove in the form of a V-shapedgroove defined by an V-shaped circumferential interior surface of thedisposable pipette tip opening toward the longitudinal axis and having aV-shaped cross section as illustrated.

FIG. 87 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device positioned inthe disposable pipette tip comprising the alternative V-shaped groovewherein the tip is lifted up to its final state with the roundedsurfaces of the plurality of segments or balls being extended into theV-shaped groove and into abutment against the V-shaped circumferentialinterior surface with the distal elastomeric element in a finalcompressed and seated sealing state against the sealing seat surface ofthe tip.

FIG. 88 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the rounded surface of one of the plurality of segmentsor balls being extended into the V-shaped groove and abutting againstthe V-shaped circumferential interior surface defining the V-shapedgroove as is illustrated in FIG. 87.

FIGS. 89 through 99 are fragmentary, longitudinal sectional, sideelevational views detailing different further example embodiments ofcircumferential annular tip grooves.

FIG. 100 is a fragmentary, longitudinal sectional, side elevationaldetailed view detailing the interior of a second example embodiment of adisposable pipette tip.

FIG. 101 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device positionedover the second example embodiment of the disposable pipette tip.

FIG. 102 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the pipette tip coupler device positioned inthe second example embodiment of the disposable pipette tip with thestop disk shoulder surface of the coupling device abutting against anaxial stop surface of the second example embodiment of the disposablepipette tip and the rounded surfaces of the plurality of segments orballs being extended against an interior surface of a circumscribingsidewall of the second example embodiment of the disposable pipette tipresulting in a deformation of the interior surface and with the distalelastomeric element in a final compressed and seated sealing stateagainst a sealing seat surface of the second example embodiment of thedisposable pipette tip.

FIG. 103 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the rounded surface of one of the plurality ofspherical balls of the pipette tip coupler device being extended againstand deforming the circumscribing sidewall of the second exampleembodiment of the disposable pipette tip.

FIG. 104 is an upper fragmentary, longitudinal sectional, top and sideperspective view detailing an upper interior of a further exampleembodiment of a disposable pipette tip comprising an interior axiallyupwardly facing shoulder seat surface having an axially upwardly facingannular groove coaxially disposed around an interior axially upwardlyextending circumscribing rib.

FIG. 105 is a fragmentary, longitudinal sectional, side elevational viewof the further example embodiment of the disposable pipette tipcomprising the interior axially upwardly facing shoulder seat surfacehaving the axially upwardly facing annular groove coaxially disposedaround the interior axially upwardly extending circumscribing rib havinga continues solid circumscribing cross section.

FIG. 106 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the further example embodiment of the disposablepipette tip illustrating detail of the axially upwardly facing annulargroove coaxially disposed around the interior axially upwardly extendingcircumscribing rib.

FIG. 107 is a fragmentary, longitudinal sectional, side elevational viewof the third example embodiment of the pipette tip coupler deviceoperatively positioned in the further example embodiment of thedisposable pipette tip comprising the interior axially upwardlyextending circumscribing rib.

FIG. 108 is a fragmentary, longitudinal sectional, side elevationaldetailed view of a distally facing axial stop shoulder surface of thethird example embodiment of the pipette tip coupler device abutting theinterior axially upwardly extending circumscribing rib of the furtherexample embodiment of the disposable pipette tip.

FIG. 109 is an exploded parts perspective view of an example embodimentof an internal seal pipette tip assembly comprising an internal sealpipette tip and an internal seal.

FIG. 110 is an upper fragmentary, longitudinal sectional, sideelevational view detailing an upper interior of an example embodiment ofthe internal seal pipette tip comprising an interior axially upwardlyfacing shoulder seat surface having an axially upwardly facing annulargroove coaxially disposed around an radially interior axially upwardlyextending circumscribing rib having a continues solid circumscribingcross section.

FIG. 111 is a fragmentary, longitudinal sectional, side elevationaldetailed view of an example embodiment of the internal seal pipette tipillustrating detail of the axially upwardly facing annular groovecoaxially disposed around the radially interior axially upwardlyextending circumscribing rib.

FIG. 112 is a fragmentary, longitudinal sectional, side elevational viewof an example embodiment of the internal seal pipette tip assemblycomprising the internal seal disposed in the axially upwardly facingannular groove.

FIG. 113 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the internal seal disposed in the axially upwardlyfacing annular groove.

FIG. 114 is a fragmentary, longitudinal sectional, side elevational viewof the third example embodiment of the pipette tip coupler devicepositioned in and operatively coupled to an example embodiment of theinternal seal pipette tip assembly.

FIG. 115 is a fragmentary, longitudinal sectional, side elevationaldetailed view of a distally facing axial stop shoulder surface of thethird example embodiment of the pipette tip compressing the internalseal disposed in the axially upwardly facing annular groove andcontacting the radially interior axially upwardly extendingcircumscribing rib disposed coaxially within and radially adjacent tothe axially upwardly facing annular groove.

Although various example embodiments may be numbered herein, theseembodiments should not be limited by these terms. These terms are onlyused to distinguish one embodiment from another. Additionally, theseterms do not imply a sequence or order.

DETAILED DESCRIPTION

For the purpose of illustrating the disclosure, there are shown in thedrawings embodiments that are presently preferred. These exampleembodiments will now be described more fully with reference to theaccompanying drawings wherein like reference numerals are used to denotelike parts or portions throughout the description of the several viewsof the drawings.

Pipette Assembly with Pipette Tip Coupler and Disposable Pipette Tip

FIGS. 1 and 2 illustrate an example embodiment of a pipette deviceassembly 10 comprising an example embodiment of a pipette device 20, anexample embodiment of a pipette tip coupler device 100, and an exampleembodiment of a disposable pipette tip 220 removably coupled to thepipette device 20 by way of the pipette tip coupler device 100.

Pipette Device 20

Referring to FIG. 2, the pipette device 20 comprises a body 22supporting an aspirating and dispensing device 24 comprising a plunger26 operatively coupled to and driven by a motor 28. The plunger 26resides within a plunger cylinder 30 extending from a distal or lowerend 32 of the body 22 of the pipette device 20. Pipette device 20further comprises an aspirating and dispensing cylinder 34 that is atleast partially disposed within plunger cylinder 30 at a locationaxially aligned with and distally below the plunger 26. The aspiratingand dispensing cylinder 34 distally transitions into a distal mountingflange 36 for attaching with the segment and seal pipette tip couplerdevice 100 that, in turn, removably couples with the disposable pipettetip 220.

Referring to FIG. 3, the aspirating and dispensing cylinder 34 furthercomprises an interior circumscribing side wall 38 that defines anopen-ended pipette channel 40 extending therethrough. The open endedpipette channel 40 longitudinally extends along a longitudinal channelaxis 80 of the pipette device assembly 10 between an open upper endportion 42 and open lower end portion 44 of the aspirating anddispensing cylinder 34 for providing open communication between plunger26 and an exterior area adjacent distal mounting flange 36 (FIG. 2)wherein the distal mounting flange 36 is operatively connected to thepipette tip coupler 100 comprising an open ended cylindrically shapedcentral channel 150 extending therethrough to provide open comminationbetween the passage opening 238 of the tip 220 and the aspirating anddispensing cylinder 34 via the pipette tip coupler 100.

Piston or Squeeze Sleeve 46

Referring to FIGS. 3 and 4, the pipette device 20 further comprises ahollow piston or squeeze sleeve 46 having a proximal or upper end 48 anda distal or lower end 50. The squeeze sleeve 46 circumscribes both theplunger cylinder 30 and the aspirating and dispensing cylinder 34 and isoperatively coupled to a squeeze motor 52.

As illustrated in FIG. 4, the squeeze motor 52 of pipette deviceassembly 10 is supported on the body 22 of the device 20 and isoperatively coupled to and drives a lead screw 54 that couples to anaxially translating lead nut 56 that is operatively coupled to a squeezelinkage 58. Additionally, the squeeze linkage 58 is operatively coupledto the proximal or upper end 48 of squeeze sleeve 46 via squeeze linkagearm 60 such that rotation of the squeeze motor 52 in a first directionresults in linear axial translation of squeeze sleeve 46 in a distal orvertically downward direction along longitudinal channel axis 80 to abutan annular wedge or squeeze ring 210 (FIG. 5) of the coupler 100 asdescribed below. Subsequent rotation of the squeeze motor 52 in a secondor opposite direction results in linear counter axial translation of thesqueeze sleeve 46 in a proximal or vertically upward direction oppositethe distal or vertically downward direction along longitudinal channelaxis 80.

Ejection Sleeve 62

Referring to FIG. 4, the pipette device 20 further comprises an ejectionsleeve 62 used to eject the disposable pipette tip 220 from the pipettedevice 20 wherein the ejection sleeve 62 is axially movable relative tothe aspirating and dispensing cylinder 34 (FIG. 2) and comprises aproximal or upper end 64, a distal or lower end 66, and an ejectionsleeve arm 68 attached at a first end to the ejection sleeve 62 adjacentupper end 64 and having an opposing second end attached to a first endof a plunger device 70.

As illustrated in FIG. 5, the plunger device 70 comprises an opposingend surface 72 abutting one end of an ejection sleeve spring 74 havingan opposing spring end abutting against an upper surface portion 76 ofthe body 22 of device 20 wherein the ejection sleeve spring 74 iscaptured between the surfaces 72, 76 to be spring loaded to bias theplunger device 70 and attached sleeve 62 in a typical pipette tipejected state.

FIG. 2 illustrates the retracted state of the ejection sleeve 62. Thetypical pipette tip ejected state is configured to require a force, suchas coupling to pipette tip 220, to overcome the ejection sleeve springforce in order to axially push the ejection sleeve 62 to a retractedstate as illustrated in FIG. 2. Additionally, FIG. 2 illustrates thatthe spring 74 circumscribes a central spring guide member 78 forretaining the shape of the spring 74 and for preclude the spring 74 frombuckling.

Furthermore, the spring 74 is dimensioned in such a way that the forceexerted on the pipette tip 220 by sleeve 62 in the course of itsrelaxation is sufficient to assist in ejecting the tip 220 from thepipette tip coupler 100.

It should be appreciated that the pipette tip coupler 100 (and coupler1100 detailed below) and the disposable pipette tip 220 can be practicedon other embodiments of pipette devices wherein the embodiment ofpipette device 20 is provided by way of example only and not limitation.

Pipette Tip Coupler 100

FIG. 5 illustrates an example embodiment of the segment and seal pipettetip coupler device 100 interposed between the disposable pipette tip 220and the air displacement pipette device 20 of the air displacementpipette device assembly 10.

As illustrated in FIGS. 5 through 7, the example embodiment of thesegment and seal pipette tip coupler device 100 is in the form of a ballpipette tip coupler device 100. In particular, the pipette tip coupler100 comprises a pipette tip coupler body 120 and a distal stem portion138, a distal elastomeric element 160 carried on the distal stem portion138, a segment or ball coupling system 180 carried at a proximate orupper end portion of the pipette tip coupler body 120 and comprising aplurality of circumferentially spaced apart spherical balls 200 and asegment or ball retainer 182 for retaining and allowing movement of theplurality of spaced apart spherical balls 200, and annular wedge orsqueeze ring 210 surmounting the plurality of spherical balls 200.

Referring to FIGS. 6 and 7, and in one example embodiment, the pipettetip coupler 100 also comprises an elongated head or shank member 102surmounting the pipette tip coupler body member 120. The pipette tipcoupler 100 further comprises the plurality of spherical balls 200carried spaced apart circumferentially at a proximate or upper endportion of the pipette tip coupler body 120 by the segment or ballretainer 182 and the lower or distal elastomeric element 160 carried ata distal or lower end portion of the pipette tip coupler body 120.Moreover, the pipette tip coupler 100 comprises an annular wedge orsqueeze ring 210 surmounting the plurality of spherical balls 200carried by the segment or ball retainer 182 such that the plurality ofspherical balls 200 are interposed between the pipette tip coupler body120 and the annular wedge squeeze ring 210 and radially moveable withinthe segment or ball retainer 182 between a radially retracted positionand a radially extended position as a function of the axial location ofthe annular wedge or squeeze ring 210.

Shank Member 102

Referring to FIGS. 6 and 7, and in one example embodiment, shank member102 comprises an annular proximal end face 104 defining a proximal orupper end face of the pipette tip coupler 100. End face 104 comprises anouter periphery 106 that can be chamfered and that transitions intoelongated tubular body 108.

Distal from proximal end face 104, the elongated tubular body 108transitions into an annular tapered portion 110 that decreases indiameter and transitions into a cylindrical neck portion 112. Thecylindrical neck portion 112 distally transitions into a cylindricalcollar 114 that has a diameter greater than a diameter of thecylindrical neck portion 112. The cylindrical collar 114 is distallyfollowed by a second cylindrical collar 116 that has a diameter greaterthan a diameter of the cylindrical collar 114 and that surmounts aninner portion of an upper circular body end surface 122 of the pipettetip coupler body 120. The second cylindrical collar 116 is an annularspacer, which may be integrated with shank member 102. Alternatively,the second cylindrical collar 116 may be replaced with a separate,removable annular spacer.

Pipette Tip Coupler Body 120 and Distal Stem Portion 138

As illustrated in FIG. 7, the pipette tip coupler body 120 comprises thesuperior or upper end surface 122 that radially and outwardly extendsfrom the distal end of the second cylindrical collar 116 and transitionsinto an outer peripheral edge 124 that is rounded. In one exampleembodiment, the upper circular body end surface 122 is a substantiallyplanar surface that radially outwardly extends from the distal end ofthe second cylindrical collar 116 to the outer peripheral edge 124.

Additionally, coupler body 120 comprises a multi-cylindrical sectioncomprising a first cylindrical or stop disk portion 130 that distallyextends axially away from upper end surface 122 and that is distallyfollowed by a second cylindrical portion 132 that is reduced in diameterfor forming a distally or downwardly facing axial shoulder surface orstop shoulder surface 134 between the adjoining first and secondcylindrical portions 130, 132.

As illustrated in FIG. 7, the second cylindrical portion 132 distallyextends from the stop shoulder surface 134 to a distally lower surface136 that radially inwardly transitions into a reduced diameter distalcylindrical stem portion 138 that terminates to a radially outwardlyextending upper surface 140 of an end plate 142 that is generally round.The end plate 142 comprises a rounded peripheral edge that provides acircumferential rounded transition between the upper surface 140 of theend plate 142 and a lower generally planar surface 144 of end plate 142defining the distal end face of the pipette tip coupler body 120 ofpipette tip coupler 100.

As illustrated in FIGS. 6 and 7, and as noted above, the secondcylindrical portion 132 is reduced in diameter relative to the firstcylindrical portion 130. Thus, the first cylindrical portion 130 has afirst diameter that is greater than a second diameter of the secondcylindrical portion 132 for forming the distally facing axial shouldersurface or stop shoulder surface 134 between the first and secondcylindrical portions 130, 132.

Furthermore, the second diameter of the second cylindrical portion 132is greater than a diameter of the end plate 142. In turn, a diameter ofthe distal cylindrical stem portion 138 is less than both the seconddiameter of the second cylindrical portion 132 and the diameter of theend plate 142 for defining a lower, distal groove 146 between the secondcylindrical portion 132 and the end plate 142. In one exampleembodiment, the first and second cylindrical head portions 130 and 132respectively comprise generally smooth exterior cylindrical surfaces andthe distal cylindrical stem portion comprises a generally smoothexterior cylindrical or groove surface.

Referring to FIGS. 7 and 13, the pipette tip coupler 100 furthercomprises an open ended, interior cylindrical channel surface 148 thatdefines an open ended cylindrically shaped central channel 150 that runsalong the longitudinal central axis 101 of the pipette tip coupler 100from the annular proximal or upper end face 104 defining the proximalend face of the pipette tip coupler 100 to the lower generally planarsurface 144 defining the distal end face of the pipette tip coupler 100.The open ended cylindrically shaped central channel 150 provides opencommunication between the aspirating and dispensing cylinder 34 (FIG. 3)and the pipette tip 220 wherein the aspirating and dispensing cylinder34 is also in open communication with the aspirating and dispensingplunger 26 (FIG. 3).

Distal or Lower Elastomeric Element 160

Referring to FIGS. 6 and 7, and as noted above, the pipette tip coupler100 comprises the ball coupling system 180 carried at the upper endportion of coupler body 120 and the lower or distal elastomeric element160 carried at the lower end portion of coupler body 120 axiallydistally spaced from the ball coupling system 180 by way of the distalcylindrical stem portion 138.

Referring to FIG. 8, and in one example embodiment, the lowerelastomeric element 160 comprises an annular body 162 having an interiorsurface 164 defining a central opening 166. The lower elastomericelement 160 further comprises a top surface 168, a peripheral exteriorsurface 170, and a bottom surface 172. In a relaxed or unsqueezed state,the lower elastomeric element 160 comprises a circumferentiallycontinuous, generally circular cross section area 174 as is illustratedin FIG. 13. Alternatively, the elastomeric element may have arectangular, X-shaped, square-shaped, or other cross sectional area.

Referring to FIGS. 7 and 8, the central opening 166 of the lowerelastomeric element 160 is dimensioned to tightly circumscribe thedistal cylindrical stem portion 138 of the pipette tip coupler 100between the distally lower surface 136 of the second cylindrical portion132 and the upper surface 140 of the end plate 142 of the pipette tipcoupler body member 120 wherein the surfaces 136,140 are in the form of,but not limited to, a planar, conical or concave configuration.

Segment or Ball Coupling System 180

Referring to FIG. 6, and in one example embodiment, the segment or ballcoupling system 180 comprises an annular crown shaped raceway 182comprising a plurality of circumferentially spaced apart guide socketsor surfaces 192 each carrying one of a plurality of segments orspherical balls 200.

Referring to FIG. 9, the annular crown shaped raceway 182 comprises anannular base 184 having an interior surface 186 defining a centralopening 188, an upper surface 190 configured with the plurality ofcircumferentially spaced apart guide sockets 192 with each adjacent pairof guide sockets 192 separated by one of a plurality of interveningfingers 194. The annular crown shaped raceway 182 further comprises aperipheral exterior surface 196 and a bottom surface 198.

Referring to FIG. 10, the segment or ball retainer 182 surmounts body120 by having a seating abutment of at least the bottom surface 198 ofthe annular crown shaped raceway 182 with the upper end surface 122(FIG. 7) of the stop disk portion 130 of the pipette tip coupler body120 wherein each of the plurality of segments or spherical balls 200 isdisposed in a different one of the plurality of the circumferentiallyspaced apart guide sockets 192.

As illustrated in FIG. 11, the spherical balls 200 are capturedvertically by a pair of opposed inwardly projecting stakes 202 disposedat the upper most portion of a plurality of adjacent pairs of theplurality of intervening fingers 194 of the annular crown shaped racewaybody 182. Additionally, each of the spaced apart guide sockets 192comprises a grooved or concaved socket seat having an outer sidewallradius 204 that capture the balls horizontally along with widthdimensions of the U-shaped ball openings defined by the spaced apartguide sockets 192 and intervening fingers 194. The spaced apart guidesockets 192 are configured for carrying radially advancing andretracting balls on the guide sockets 192 for attachment and detachmentof the tip 220.

Accordingly, and with reference to FIGS. 10 and 11, the segment or ballcoupling system 180, comprising the raceway 182 and the plurality ofspherical balls 200, disposed on the upper end surface 122 of the stopdisk portion 130 of the pipette tip coupler body 120 retains theplurality of spherical balls or segments and allows movement of thespherical balls or segments between extended and retracted position. Thesegment or ball coupling system 180 may be operatively fitted on orintegrally formed operatively with upper end surface 122 of the stopdisk portion 130 of the pipette tip coupler body 120.

Annular Wedge or Squeeze Ring 210

Referring to FIGS. 12 and 13, an embodiment of the pipette tip coupler100 comprises the annular wedge or squeeze ring 210. Squeeze ring 210comprises a resilient wedge shaped annular body 211 having acircumferentially continuous, generally wedge shaped or triangularshaped cross section 212 with a radially extending annular lip 218 asillustrated in FIG. 13. As illustrated in FIG. 12, annular body 211comprises a central interior annular surface 213 defining a centralannular opening 214 extending through the annular body 211. Furthermore,wedge shaped annular body 211 comprises a top planar circular surface215 radially outwardly extending from the central interior annularsurface 213 to a circumscribing outer edge surface 216. Moreover, wedgeshaped annular body 211 comprises a radially outwardly proximallyinclined side surface 217 radially upwardly tapering from a bottomannular end 219 to an underside of annular peripheral lip 218 (FIG. 13)that radially extends outwardly and terminates to circumscribing outeredge surface 216.

As illustrated in FIG. 13, the central annular opening 214 of theannular wedge or squeeze ring 210 is dimensioned to allow passage of theshank member 102 so as to allow a seating abutment of radially outwardlyproximally inclined side surface 217 of the annular wedge or squeezering 210 with, as illustrated in FIG. 6, the plurality of segments orspherical balls 200 of the segment or ball coupling system 180 carriedon the upper end surface 122 (FIG. 7) of the stop disk portion 130 ofthe pipette tip coupler 100.

Referring to FIG. 13, the shank member 102 of the pipette tip coupler100 is configured to fit within the distal mounting flange 36 of theaspirating and dispensing cylinder 34 (FIG. 2) for operatively couplingthe pipette tip coupler 100 to the pipette device 20 of the pipettedevice assembly 10 and aligning axis 101 (FIG. 6) of the coupler 100with axis 98 (FIG. 14) of the pipette device 20. In one embodiment, theelongated tubular body 108 of the shank member 102 is externallythreaded to mount, or screw, into distal mounting flange 36 that hasmating internal threads.

Actuation of Squeeze Motor

With the pipette tip coupler 100 fitted within the distal mountingflange 36 as illustrated in FIG. 13, the top planar circular surface 215of the annular wedge or squeeze ring 210 is adjacent the distal end 50of the squeeze sleeve 46. Accordingly, actuation of the squeeze motor 52(FIG. 1) in the first direction results in linear axial translation ofthe squeeze sleeve 46 in a distal or vertically downward direction forapplying a force axially on the top surface 215 of the annular wedgesqueeze ring 210 via a liquid level detection (LLD) circuit ring end 366detailed below for forcing the wedge shaped bottom 217 to push uniformlyagainst the inner surfaces of plurality of spherical balls 200 forpushing them radially out and into a groove 246 (FIG. 16) of thedisposable pipette tip 220 and into contact with surface 244 (FIG. 16)as exemplified in FIG. 23 described below.

Subsequent actuation of the squeeze motor 52 (FIG. 1) in a seconddirection, opposite the distal or vertically downward direction, returnsthe distal end 50 of the squeeze sleeve 46 to a home position asillustrated in FIG. 13 such that the annular wedge or squeeze ring 210axially slides up thereby allowing the plurality of segments orspherical balls 200 to freely radially retract on respective spacedapart grooved or concave guide sockets 192 (FIG. 11) from the groove 246(FIG. 16) of the disposable pipette tip 220 (FIG. 16). Thus, when theeject sleeve 62 (FIG. 13) pushes on the tip 220 (FIG. 16), the surface244 (FIG. 16) of the groove 246 and the interior circumferential surfaceaxially above the groove 246 push upon contact of the segments orspherical balls 200 thereby causing the segments or spherical balls 200to retract.

Pipette Tip 220

As illustrated in FIGS. 2 and 14, and as noted above, the pipette tipcoupler 100 provides an open communication coupling between thedisposable pipette tip 220 and the pipette device 20 of the pipettedevice assembly 10.

Referring to FIGS. 14 through 16, and in one example embodiment, thedisposable pipette tip 220 comprises an elongated tubular pipette tipbody 222 having a central longitudinal axis 224. Pipette tip body 222comprises an elongated circumscribing sidewall 226 longitudinallyextending along the central longitudinal axis 224 between a proximal orupper annular end face 228 and a distal or lower annular end face 230defining circumscribing open proximal and distal annular ends 232 and234 respectively. The elongated circumscribing sidewall 226 comprises aninterior surface 236 defining a pipette tip passage opening 238extending longitudinally along the central longitudinal axis 224 of thepipette tip body 222 between the open upper annular end 232 and the openlower annular end 234.

Accordingly, the pipette tip passage opening 238 provides opencommunication from an area exterior to the open distal annular end 234(FIG. 16), through the pipette tip 220, and to the pipette devicechannel 40 by way of the central channel 150 of the pipette tip coupler100 (FIG. 3) when the pipette tip coupler 100 is coupled between thepipette device 20 and the pipette tip 220. In this couplingconfiguration, the central longitudinal axis 224 of the pipette tip body222 is coextensive with the longitudinal channel axis 80 of the pipettedevice 20.

First Interior Surface Section

Referring to FIG. 16, and in one example embodiment, the interiorsurface 236 of the elongated circumscribing sidewall 226 comprises anuppermost annular chamfered interior surface 240 that distally extendsradially inward from the proximal annular end face 228 of the pipettetip 220 and terminates by transitioning into a first substantiallycylindrical interior surface section 242 having a first diameter.

Axially Arcuate Circumferential Surface Defining a Groove

As illustrated in FIG. 16, and in one example embodiment, the firstsubstantially cylindrical interior surface section 242 comprises anaxially arcuate circumferential interior surface 244 formed into theelongated circumscribing sidewall 226 defining a circumferential annulargroove 246. Annular groove 246 divides the first substantiallycylindrical interior surface section 242 into an upper firstsubstantially cylindrical interior surface portion and a lower firstsubstantially cylindrical interior surface portion of substantiallyequal diameter. Accordingly, the annular groove 246 provides acircumferential radially outwardly extending concavity shaped interiorsurface interruption of the first substantially cylindrical interiorsurface section 242 with an arcuate surface longitudinal cross section.The arcuate circumferential interior surface 244 is also configured inalternative surface cross sections as discussed below. And in oneembodiment, the first substantially cylindrical interior surface section242 is devoid of arcuate circumferential interior surface 244 definingthe circumferential annular groove 246 as discussed below.

Referring to FIGS. 16 and 17, the axially arcuate circumferentialinterior surface 244 defining the annular groove 246 comprises an upperannular transition edge 248 distally transitioning into an upper axiallyarcuate circumferential surface sector portion 250 of the axiallyarcuate circumferential interior surface 244. In succession, the upperaxially arcuate circumferential surface sector portion 250 distallytransitions into a lower axially arcuate circumferential surface sectorportion 252 of the axially arcuate circumferential surface 244. Then,lower axially arcuate circumferential surface sector portion 252terminates to a lower annular transition edge 254.

The upper axially arcuate circumferential surface sector portion orupper portion 250 provides the annular groove 246 with an increasingradius relative to the central longitudinal axis 224 of the pipette tip220 from the upper annular transition edge 248 to a maximum radius ofthe annular groove 246 relative to the central longitudinal axis 224that defines a circumferential annular center of the annular groove 246.

The lower axially arcuate circumferential surface sector portion orlower portion 252 provides the annular groove 246 with a decreasingradius relative to the central longitudinal axis 224 of the pipette tip220 from the maximum radius defining the circumferential annular centerof the of the annular groove 246 to the lower annular transition edge254.

Second Interior Surface Section and Annular Shoulder Stop Surface

As illustrated in FIG. 16, the first substantially cylindrical interiorsurface section 242 is axially distally proceeded by a secondsubstantially cylindrical interior surface section 262 having a seconddiameter less than the first diameter of the first substantiallycylindrical interior surface section 242 for forming a proximallyfacing, radially inwardly extending annular shoulder seat surface oraxial stop surface 260 interposed between the first and secondsubstantially cylindrical interior surface sections 242, 262.

In one example embodiment, the proximally facing axial stop surface 260is substantially planar and generally perpendicular to the centrallongitudinal axis 224 of the pipette tip body 222.

Third Interior Surface Section and Sealing Seat

As illustrated in FIG. 17, the second substantially cylindrical interiorsurface section 262 is axially distally proceeded by a thirdsubstantially cylindrical interior surface section 272 having a thirddiameter less than the second diameter of section 262.

Interposed between the second section 262 and the third section 272 is afrustoconical annular sealing seat or stop surface 270 defining acircumferential radially inwardly angled and distally extending distalworking surface 270 as illustrated in FIG. 17. The frustoconical annularsealing seat surface 270 comprises an upper annular sealing seat edge266 defining an annular border between the second substantiallycylindrical interior surface section 262 and the frustoconical annularsealing seat surface 270.

In addition, the frustoconical annular sealing seat surface 270comprises a lower annular sealing seat edge 268 defining an annularboarder between the frustoconical annular sealing seat surface 270 andthe third interior surface section 272 wherein a diameter of the upperannular sealing seat edge 266 is greater than a diameter of the lowerannular sealing seat edge 268.

Accordingly, the frustoconical annular sealing seat surface 270 definesthe circumferential radially inwardly angled and distally extendingdistal working surface, abutment, or sealing seat surface 270 interposedbetween the second substantially cylindrical interior surface section262 and the third substantially cylindrical interior surface section272.

As illustrated, the sealing seat surface 270 is disposed at an acuteangle relative to the central longitudinal axis 224 wherein the acuteangle defines an acute sealing seat surface angle relative to thecentral longitudinal axis 224. In one embodiment, the preferred acutesealing seat surface angle relative to the central longitudinal axis 224is about 15 degrees to about 35 degrees with a preferred angle of abouttwenty-five degrees.

In one alternative embodiment, the sealing seat surface 270 is providedwith an alternative sealing seat surface angle of substantially ninetydegrees relative to the central longitudinal axis of the pipette tip.This embodiment is illustrated in FIG. 76 wherein the sealing seatsurface angle of an alternative sealing seat surface 2270 relative tothe central longitudinal Z-axis is substantially 90 degrees.

Lower Interior Surface Portion

FIG. 16 further illustrates that in succession to the thirdsubstantially cylindrical interior surface section 272 is a fourthinterior surface section 274 that is distally followed by a fifthinterior surface section 275.

In one example embodiment, the fourth interior surface section 274distally tapers or decreases in diameter from a distal annular end 276of the third substantially cylindrical interior surface section 272 to aproximal annular end 278 of the fifth interior surface section 275. Inturn, the fifth interior surface section 275 distally tapers ordecreases in diameter from the proximal annular end 278 of the fifthinterior surface section 275 to the open distal annular end 234 of thepipette tip 220 that is intended for immersion. Additionally, and in oneexample embodiment, the fifth interior surface section 275 has a greatertaper than the fourth interior surface section 274.

External Longitudinal Ribs

Referring to FIG. 15, and in one example embodiment, of the pipette tip220 comprises a plurality of circumferential spaced apart longitudinallyextending external ribs 280 disposed on the tubular pipette tip body 222adjacent to the periphery of the proximal annular end face 228 andlongitudinally extending externally therefrom to an exterior area of thecircumscribing sidewall 226 that is adjacent to the third substantiallycylindrical interior surface section 272 as illustrated in FIG. 16.

In one example embodiment, and as illustrated in FIG. 15, the pluralityof circumferential spaced apart longitudinally extending external ribs280 may be utilized to provide support for the pipette tip 220 on or ina support surface 282 that the pipette body 222 has passed through via,for example, a support surface aperture opening 284. One exampleembodiment of the support surface 282 can be in the form of, but notlimited to, lab ware in the form of a tip rack as is known in the art,and informed by the present disclosure.

Automated Pipetting Workstation or System

Referring to FIGS. 1 and 18, and in one example of use and operation,one or more of the pipette device assemblies 10 is employed in anautomated pipetting workstation or system 300 that generally provides,but is not limited to, programmed transfers of liquid between containersthat comprises mounting and ejection processes of one or more disposablepipette tips 220 to the pipette tip coupler 100 operatively carried bythe pipette device 20 for carrying out, for example, the programmedtransfers of liquid between containers.

In one example embodiment, the automated pipetting workstation 300generally comprises a robotic gantry 302 that carries at least onepipette device assembly 10 vertically above a horizontally disposedworkstation deck 304. The pipette device assembly 10 can comprise asingle channel pipetting head or a multi-channel pipetting head.

Additionally, the robotic gantry 302 typically provides two or threedegrees of freedom wherein three degrees of freedom compriseslongitudinal translation along an axis defining an X-axis, latitudinaltranslation along an axis defining a Y-axis, and vertical (up and down)translation along an axis defining a Z-axis so that the pipette deviceassembly 10 can move along the length (X-axis) and width (Y-axis) of thedeck and vertically up and down (Z-axis) relative thereto. With twodegrees of freedom, the robotic gantry is typically provided with theability to translate the pipette device assembly 10 vertically andeither longitudinally or laterally.

In one example embodiment, the automated pipetting workstation 300further comprises a main controller 306, a pipette axis controller 308,and a power supply 310 that provides power for the main controller 306,the pipette axis controller 308, and the pipette device assembly 10.

Additionally, and in one example embodiment, a computer/controller 320can also be employed with the workstation 300 and communicate with themain controller 306 and the pipette axis controller 308 for controllingthe robotic gantry 302 and pipette device assembly 10 including theassociated process protocols of the pipette device assembly 10 such asthe disposable pipette tip 220 attaching and ejection (coupling anddecoupling) processes detailed below.

In one example embodiment, the computer/controller 320 typicallycomprises a processor device or central processing unit (CPU) 322, ahardware read only memory device (ROM) 324, a hardware main memorydevice (RAM) 326, a hardware storage memory 328 comprising anon-transitory computer readable medium or memory 330 having anoperating system 332 and software 334 such as user defined processes 336for the pipette device assembly 10 stored thereby, a user display 338, auser input device 340, an input interface 342, an output interface 344,a communication interface device 346, and a system bus 348 thatcomprises one or more conductor or communication paths that permitcommunication among the devices of the computer/controller 320.Computer/controller 320 may also be operatively couple to LAN and/orserver 350. A power supply 352 provides power for thecomputer/controller 320.

Examples of the above delineated automated pipetting workstation 300including software are presently manufactured and sold by HamiltonCompany, the assignee of the present patent application, located at 4970Energy Way, Reno, Nev. 89502, United States of America.

Pipette Tip Pickup Process with Pipette Tip Coupler 100

FIGS. 19 through 25 illustrate details of an example embodiment ofsuccessive stages of a pipette tip pickup process and, in particular, amethod of securing attachment of the pipette tip 220 to the pipette tipcoupler 100 operatively carried by the pipette device 20. As notedabove, and in one example embodiment, the pipette tip 220 may besupported by the support surface 282.

As illustrated in FIG. 19, the pipette tip coupler 100 is connected tothe pipette device 20, and upon command, the pipette tip coupler 100 ispositioned over the open proximal end 232 of the pipette tip 220 whereineach of their respective central longitudinal axes is aligned along theZ-axis. The eject sleeve 62 is in the eject position, the squeeze sleeve46 is in the unsqueezed position, the segment or ball coupling system180 is in the relaxed state, and the distal O-ring 160 is in theunsqueezed state.

Next, FIG. 20 illustrates the pipette tip coupler 100 being moved downalong the Z-axis into the pipette tip 220 for lowering the distal,elastomeric carrying portion of the pipette tip coupler 100 to pass intothe interior cylindrical proximal end portions of the pipette tip 220 tobring the plurality of segments or spherical balls 200 into contact withthe chamfered interior surface 240 of the tip 220 tip while maintainingthe distal O-ring 160 in the unsqueezed state and before the annularshoulder seat or stop surface 260 of the pipette tip 220 and the axialstop shoulder surface 134 of the stop disk 130 are mated.

Next, FIG. 21 illustrates the pipette tip coupler 100 being moved downalong the Z-axis and the squeeze sleeve 46 being moved down along theZ-axis into contact with the annular wedge squeeze ring 210 thatsurmounts the plurality of spherical balls 200 for lowering the distalelastomeric carrying portion of the pipette tip coupler 100 to pass intothe interior cylindrical proximal end portions of the pipette tip 220 tobring the distal O-ring 160 into contact with the tip annular sealingseat or stop surface 270 while maintaining the plurality of sphericalballs 200 in the unsqueezed state and before the annular shoulder seator stop surface 260 of the pipette tip 220 and the axial stop shouldersurface 134 of the stop disk 130 are mated such that a gap 298 ismaintained between the annular shoulder seat or stop surface 260 of thepipette tip 220 and the axial stop shoulder surface 134 of the stop disk130.

Next, FIG. 22 illustrates the squeeze sleeve 46 being moved further downalong the Z-axis for pushing against the LLD circuit ring end 366 thatmakes contacts with and pushes against the annular wedge squeeze ring210 that pushes down onto the plurality of spherical balls 200 forstarting the process of squeezing or pushing the spherical balls 200into the groove 246 and initially into abutment with the upper axiallyarcuate circumferential surface sector portion 250 (FIG. 17) of theaxially arcuate circumferential interior surface 244 (FIG. 16) definingthe groove 246 wherein the action of the plurality of spherical balls200 extending or being projected into the groove 246 causes an axialupward force that pulls the pipette tip 220 axially up.

As a result, and referring to FIGS. 21 and 22, this starts a process ofseating the proximally or upwardly facing annular shoulder seat surface260 of the pipette tip 220 with the distally or downwardly facing axialstop shoulder surface 134 of the stop disk 130 for closing the gap 298and concurrently compressing the distal or lower O-ring 160 with thesealing seat or stop surface 270 of the tip 220.

FIG. 23 illustrates the squeeze sleeve 46 being moved down along theZ-axis a pre-calibrated or predetermined length until it is locked inposition resulting in the annular wedge or squeeze ring 210 beingstopped and locked in position by the squeeze sleeve 46. As a result,the spherical balls 200 are radially extended to a desired distance orvalue (FIG. 24) for fully seating the axial stop shoulder surface 134 ofthe pipette tip coupler 100 against the annular shoulder seat surface260 of the pipette tip 220 with the seating of the two surfaces 134, 260along the X-axis (FIG. 19) substantially perpendicular to the Z-axis(FIG. 19) for forming a normal datum between the two axis while thedistal O-ring 160 is compressed to a desired distance or value (FIG. 25)for seating the distal O-ring 160 with the annular sealing seat or stopsurface 270 of the tip 220 such that its cross-section is in its finalcompressed non-circular form thereby completing the coupling of thepipette tip coupler 100 with the pipette tip 220.

Upon completion of the securing attachment process as illustrated inFIG. 23, the segment or ball coupling system 180 and the distalelastomeric element 160 work in combination to produce a segment andseal coupling between tip 220 and coupler 100 that provides afluid-tight seal wherein the plurality of spherical balls 200 are atleast partially received within the circumferential groove 246 and atleast partially seated on the circumferential arcuate interior surface244 defining the circumferential groove 246 and wherein the distalelastomeric element 160 seals against the radially inwardly angled anddistally extending surface 270 of the pipette tip 220 in a storage stateof elastic potential energy.

In one aspect, and referring to FIGS. 19 through 25, the segment or ballcoupling system 180 comprises the peripheral circumferentially spacedapart guide sockets 192 (FIG. 9) configured for carrying radiallyadvancing and retracting balls for attachment and detachment of the tip220 wherein the balls move radially outward to engage thecircumferential groove 246 of the tip 220 for coupling and wherein theballs move radially inward for releasing the tip 220 as a function ofaxial movement of the annular wedge or squeeze ring 210. In particular,movement of the annular wedge or squeeze ring 210 axially downwardsresults in the plurality of spherical balls 200 being urged to aradially outward position and release of pressure on the annular wedgeor squeeze ring 210 results in a release of the plurality of sphericalballs 200 from the radially outward position whereby the plurality ofspherical balls 200 are free to move radially inward.

In another aspect, the rigidity of the plurality of spherical balls 200provides a more rigid coupling for providing a stiffer joint between thepipette tip 220 and coupler 100. Furthermore, the rigidity androtatability of the plurality of spherical balls 200 provides contactsof the balls with the interior of the disposable pipette tip 220 to belargely rolling contacts thereby precluding wear and increasing couplerlife.

Disposable Pipette Tip Ejection Process

FIGS. 19 through 25 illustrate, in reverse, details of successive stagesof an example method or process of ejecting the pipette tip 220 from thepipette tip coupler 100 operatively carried by the pipette device 20.This tip ejection process sequence is similar to the attachment or tippickup securing process sequence except in reverse. Also, as describedbelow and illustrated in FIG. 28, a distal O-ring axial force componentof the compressed distal O-ring 160 provides a force to help remove thetip 220 during the ejection process.

In one example embodiment, and referring to FIGS. 19 through 25, theejection process comprises the steps of: (1) positioning the tip whereit is to be discarded, such as a waste container; (2) moving the squeezesleeve 46 upward wherein force is released from the annular wedge orsqueeze ring 210 and, as a result, this force is also released from theplurality of spherical balls 200 so as to allow retraction from thegroove 246 in the tip 220 by moving on the respective plurality ofcircumferentially spaced apart guide sockets 192, the distal O-ring 160starts to release stored elastic potential energy as a force against thetip 220, and wherein the spring loaded eject sleeve 62 also pushesagainst the tip 220 to push it off such that the tip begins to releasefrom the plurality of spherical balls 200 and coupler body member 120;(3) continue moving the squeeze sleeve 46 upward wherein the pluralityof spherical balls 200 continue to retract from the groove 246 in thetip 220 and wherein the distal O-ring 160 and the spring loaded ejectsleeve 62 pushes against the tip 220 to push it off wherein the tip 220continues to release from the plurality of spherical balls 200 and thecoupler body member 120; (4) continue moving the squeeze sleeve 46 toits up most position wherein the spherical balls 200 return to theiroriginal free position and are completely free of the groove 246 in thetip 220 and wherein the distal O-ring 160 returns to its original shapeand the spring loaded eject sleeve 62 pushes against the tip 220 untilthe tip is pushed off of the coupler body member 120 by the springloaded eject sleeve 62 and the spring loaded eject sleeve 62 becomesfully extended.

In light of the foregoing, those skilled in the art will appreciate thatthe above described tip mounting and ejection processes are applicableto a wide range of mechanically and/or automatically driven pipettetypes and designs.

Coupling and Ejection Forces

FIG. 26 illustrates a diagrammatical vector diagram of the plurality ofspherical balls 200 of the pipette tip coupler 100 initially extendinginto the groove 246 with the plurality of spherical balls 200 contactingthe upper corner of the tip groove above the center of the ballresulting in an axial upward force pulling the pipette tip 220 upward.As illustrated in FIG. 26, the ball force (Fball_resultant) for eachball is comprised of two components: an axial force (Fball_axial)component and a radial force (Fball_radial) component.

As long as the plurality of spherical balls 200 are contacting the uppercorner of the tip groove above the center of the ball, Fball_axialincreases as the distance between the ball center and corner of thegroove increases. Accordingly, at the beginning of the tip pickupprocess, the ball axial force (Fball_axial) starts out low asillustrated in FIG. 26 and, in detail in FIG. 27, and increases to itsmaximum at the end of the tip pickup process as illustrated in FIG. 28.

Referring to FIG. 27, the ratio of Z/R equals SIN (ω) and SIN (ω) isequal to (Fball_axial)/(Fball_resultant). As a result, (Fball_axial) isequal to (Fball_resultant) multiplied by the ratio of Z/R. From this,the result is that (Fball_axial) increases as Z increases.

Referring to FIG. 28, the ball axial force (Fball_axial) seats the stopdisk 130 against the tip 220 and provides the force required to overcomean O-ring axial force (Fdistal_ring_axial) and compress the distalO-ring 160. The O-ring 160 has an O-ring force (Fdistal_ring_resultant)that results from being compressed and this O-ring force comprises twocomponents: an axial component (Fdistal_ring_axial) and a radialcomponent (Fdistal_ring_radial). Additionally, the ball radial force(Fball_radial) provides the radial force needed to lock the ball 200into the tip groove 246 (FIG. 27) and the distal O-ring radial forcecomponent (Fdistal_ring_radial) provides the radial force needed tomaintain the seal against the tip. Furthermore, the ball to tip groovegeometry that causes Fball_axial to increase as the ball enters thegroove (increasing dimension Z) helps to overcome the O-ring axial force(Fdistal_ring_axial) so that the distal O-ring 160 can be completelycompressed to the desired extent. Moreover, the distal O-ring axialforce component (Fdistal_ring_axial) provides force to help remove thetip 220 during the ejection process.

Alignment/Misalignment

Referring to FIGS. 26 through 30, the axial shoulder surface 134 ofcoupler body member 120 and the axial shoulder seat 260 of tip 220 areimportant for correct tip alignment. Accordingly, the coupler 100 andtip 220 are configured so that the plurality of spherical balls 200 pushthe axial shoulder surface 134 and the axial shoulder seat 260 togetherto preclude misalignment because if the shoulders are not properlymated, especially if they are tilted, the misalignment error (E) issignificant as illustrated in FIGS. 29 and 30.

For example, and as illustrated in FIGS. 29 and 30, the relationshipbetween the misalignment angle (Ø), the tip axial distance (D) andpositional error (E) is: E=D*TAN (Ø). For example, with a misalignmentangle (Ø) of two degrees and a tip axial distance of ninety millimeters,the positional error (E) is 3.14 millimeters. This is considered to bevery high considering typical positional error tolerances are typicallyplus or minus 0.5 millimeters.

FIG. 31 illustrates correct tip alignment that maintains a tip axialdistance D measured from the tip seat 260 to the distal end 230 constantto establish a known and controlled distance of the pipette tip end 230along the vertical or axial axis Z and a perpendicular axis Xillustrated in FIG. 28. This is important to allow the pipette device totarget small holes and small volumes of liquid. Additionally, smallervolumes of liquid can be transferred resulting from the known fixeddistance of the pipette tip allowing for a controlled touch of thepipette tip/liquid to the working surface 290 onto or from which liquid292 is to be transferred.

Dimensions and Relationships

For proper use and operation, and referring to FIGS. 6 through 17, thedimensions between the coupler 100 and tip 220 are related accordingly.In particular, tip internal diameters of first section 242 and secondsection 262 must be larger than the diameter of the first cylindricalportion and the second cylindrical portion 130, 132 respectively.However, they must not be too much bigger, as this may result in a poorfit and/or misalignment.

Additionally, the diameter of tip groove 246 must be large enough toallow the plurality of spherical balls 200 to pull the tip up adequatelylock the tip 220 in place. Conversely, if it is too big, the pluralityof spherical balls 200 may not be able to be radially extended orprojected sufficiently to get a good lock and/or seal.

The dimension between tip seat 260 and an axial center of the groove 246is matched to the dimension between the stop disk seat 134 and thelocation of the center of one of the plurality of balls 200 as, forexample, illustrated in FIG. 28 for providing proper coupling betweenthe tip 220 and coupler 100.

The tip seat 260 to distal O-ring seal land 270 dimensions must matchthe stop disk seat 134 to distal O-ring groove 146 dimension. Thesedimensions control the amount that the distal O-ring 160 is compressed,and thus how well it seals.

Referring to FIGS. 28 and 31, the tip seat 260 to distal end 230 axialdimension D along with the mating of the coupling seats establish aknown and controlled distance of the pipette tip end 230 along thevertical or axial axis Z and the perpendicular axis X. This is importantto allow the pipette device to target small holes and small volumes ofliquid. Additionally, smaller volumes of liquid can be transferredresulting from the known fixed distance of the pipette tip allowing fora controlled touch of the pipette tip/liquid to the working surface 290onto or from which liquid 292 is to be transferred. As illustrated, inFIG. 28 the fully mated tip and stop disk seating/coupling surfaces 134,260 provide proper alignment and maintain the tip axial distance D.

Liquid Level Detection (LLD) Circuit Contacts

Referring to FIG. 32, and in one example embodiment, the pipette deviceassembly 10 further comprises a liquid level detection circuit assembly.The liquid level detection circuit assembly comprises a liquid leveldetection or LLD circuit board 360 comprising processing circuitry 362electrically coupled to a LLD circuit contact 364 operatively coupled tothe squeeze sleeve 46 that is made from an electrically non-conductingmaterial so it is insulated from the rest of the assembly and whereinthe contact 364 terminates to a circuit contact ring end 366 recessed inthe bottom area of the squeeze sleeve 46 that is configured forselectively contacting the circuit contact ring end 366 with annularwedge 210 between the non-contact state illustrated in FIG. 19 and thecontact state illustrated in FIG. 23 and therefore in contact with theplurality of conductive segments or spherical balls 200 coupling withthe interior first working surface of tip 220 such as the tip groove 246of the tip 220. As a result, this completes the circuit between theprocessing circuitry 362 of the LLD circuit board 360 and the tip 220.

Additionally, the stop disk mounting post or distal mounting flange 36is made from a non-conducting material. Therefore, the body member 120and the ball coupling system 180 are insulated from the rest of theassembly.

Furthermore, the processing circuitry 362 of the LLD circuit board 360detects a signal change when the tip 220 contacts liquid thereby havingan ability to detect a surface of a liquid being transferred or asurface onto or from which liquid is being transferred. Again, actuationoccurs when the coupler 100 is attached to the tip 220 and the pluralityof spherical balls 200 are radially pushed circumferentially and lockedinto the tip groove of the tip 220.

ALTERNATE EMBODIMENTS

FIGS. 33 through 36 illustrate assembly perspective views of a ballcoupling system 400 that is an alternate example embodiment of the ballcoupling system 180 (FIG. 6) for substitute use. In one embodiment, theball coupling system 400 comprises a ring-shaped raceway body 402comprising a plurality of circumferentially spaced apart guide socketsor surfaces 492 each radially movably carrying one of a plurality ofsegments or spherical balls 410. The ring-shaped raceway body 402further comprises a plurality of circumferentially spaced apart circularball openings 404 for receiving and retaining the respective pluralityof radially extended balls 410 therein wherein the balls 410 arecaptured by the circular ball openings 404 and retaining stakes 406 asillustrated in detail in FIG. 36.

FIGS. 37 through 40 illustrate assembly perspective views of a pipettetip coupler 500, that is an alternate example embodiment for substituteuse of ball coupling system 180, shank member 102, and body 120illustrated in FIG. 6.

As illustrated in FIGS. 37 through 40, the pipette tip coupler 500comprises a ring-shaped raceway body member 502 comprising a pluralityof circumferentially spaced apart circular ball openings 504 receiving aplurality of balls 520 therein and captured by a press fitted or adheredball keeper retaining ring 506 as illustrated in detail in FIG. 40.

The pipette tip coupler 500 further comprises an annular spacer 508circumscribing a shank portion 510 adjacent an upper surface 512 of adisk 514 and an annular magnet 516 surmounting the annular spacer 508for pulling the plurality of balls 520 into the raceway body member 502.

As illustrated, the body member 502 has a diameter greater than adiameter of the disk 514 such that its bottom peripheral lip defines adistally facing axial shoulder surface or stop shoulder surface 522analogous to stop shoulder surface 134 (FIG. 6).

Pipette Tip Coupler 700

Referring to FIGS. 41 and 42, a pipette tip coupler device 700 isillustrated that is an alternate example embodiment of the pipette tipcoupler 100 for alternative use wherein the pipette tip coupler device700 is configured to be coupled between the disposable pipette tip 220and the air displacement pipette device 20 of the air displacementpipette device assembly 10 (FIG. 1) utilizing the coupling processdetailed above. The pipette tip coupler 700 comprises a central couplingmember 702 that further comprises an elongated head or shank member 704,a body member 706, and distal stem portion 708. As illustrated, theshank member 704 includes a top end 710 and a distal end thattransitions into an upper surface 712 of the body member 706. The bodymember 706 comprises a lower end that transitions into the distal stemportion 708. The distal stem portion 708 terminates to an end plate 714that is generally round having a bottom end surface 716.

In one embodiment, the body member 706 has a diameter greater than adiameter of the shank member 704 and the distal stem portion 708. Asillustrated, the ball segment and seal pipette tip coupler device 700further comprises a distal elastomeric element 718 circumscribing thedistal stem portion 708 wherein the distal elastomeric element 718 isconfigured analogous to element 160 (FIG. 6).

As illustrated in FIGS. 41 and 42, the pipette tip coupler device 700also comprises a ball segment coupling system 720 disposed about theshank member 704 and mounted on body member 706. Additionally, thepipette tip coupler device 700 further comprises an annular wedge orsqueeze ring 210 or 810 (detailed below) that is disposed about theshank member 704 and that surmounts the ball segment coupling system720.

Referring to FIGS. 41 through 43, the ball segment coupling system 720comprises a cylindrically shaped raceway body member 722 comprising anannular base 724 having a central opening 726 and an outer peripherytransitioning into an upwardly extending circumscribing sidewall 728terminating into a plurality of circumferentially spaced apart circularnotched openings 730 each having a radially extending ball seatingsurface 732 thereby defining a raceway of ball seating surfaces 732radially spaced from the shank member 702 such that a radially extendingannular gap is formed between the openings 730 and the shank member 702.

As illustrated in FIG. 42, the pipette tip coupler device 700 furthercomprises an annular magnet 736 disposed about shank member 704 andmounted on the inner upper surface of the annular base 724 of theraceway body member 722 (FIG. 41). The pipette tip coupler device 700further comprises an annular spacer 738 disposed about shank member 704and surmounting the annular magnet 736. The annular magnet 736 isdimensioned to have a diameter greater than the annular spacer 738 fordefining a radial gap 740 between the annular spacer 738 and thecircular notched openings 730 of the raceway body member 722 wherein theannular magnet 736 provides a normal tendency to magnetically attract aplurality of ferrous metal balls 742 of system 720 that are disposed inthe ball seating surfaces 732 of the circular notched openings 730 intothe radial gap 740 toward the annular magnet 736. In one embodiment, theannular magnet 736 is a slip fit and the annular spacer 738 is a pressfit, and also retains the annular magnet 736 in place.

Referring to FIGS. 44 through 48, the raceway body member 722 is alignedwith and mounted on the body member 706 of the central coupling member702 that is followed by the sequential mounting of the annular magnet736 and the annular spacer 738 on the body member 706 of the centralcoupling member 702 and within the cylindrically shaped raceway bodymember 722. Then, the plurality of cylindrical balls 742 arerespectively received through the notched openings 730 and preventedfrom escaping out the openings 730 by a snap ring 744 being received ina retaining groove 746 circumscribing the upper outer peripheral surfaceof the raceway body member 722. Snap ring 744 closes notches 748 of thecircular notched openings 730 capturing the balls while allowing radialmovement of the balls on the seating surfaces 732 of the raceway bodymember 722.

Referring to FIG. 42, the raceway body member 722 has an outer diametergreater than an outer diameter of the pipette tip coupler body member706 of the central coupling member 702 such that a bottom peripheral lipis formed having a distally facing axial stop shoulder surface 750 thatis functionally analogous to stop shoulder surface 134 (FIG. 6) of thecoupler device 100.

As further illustrated in FIG. 42, the central coupling member 702comprises an open ended, interior cylindrical channel surface 752 thatdefines an open ended cylindrically shaped central channel 754 that runsalong the longitudinal central axis 734 of the pipette tip coupler 700from the annular proximal or top end 710 defining the proximal end faceof the pipette tip coupler 700 to the bottom end surface 716 of endplate 714 defining the distal end face of the pipette tip coupler 700.The open ended cylindrically shaped central channel 754 provides opencommunication between the aspirating and dispensing cylinder 34 (FIG. 3)and the pipette tip 220 wherein the aspirating and dispensing cylinder34 is also in open communication with the aspirating and dispensingplunger 26 (FIG. 3).

Annular Wedge or Squeeze Ring 810 Comprising Ball Concavities 830

FIG. 49 illustrates an annular wedge or squeeze ring 810 that comprisescircumferentially spaced apart concave faces or concavities 830 and thatis an alternate example embodiment of annular wedge or squeeze ring 210for alternative use.

FIG. 50 illustrates the pipette tip coupler device 700 employing thesqueeze ring 810 as an alternative to squeeze ring 210 (FIG. 6). Asillustrated, the curvature of each of the circumferentially spaced apartconcave faces or concavities 830 is complemental in shape to the arcuateshape of each of the plurality of segments or balls 742 for complementalsurface abutment therebetween as illustrated wherein the plurality ofsegments or balls 742 are configured analogous to the plurality ofsegments or balls 200 (FIG. 6).

Referring to FIGS. 49 and 50, and analogous to squeeze ring 210, thesqueeze ring 810 comprises a resilient annular body 812 having a centralinterior annular surface 814 defining a central opening 816 extendingthrough the annular body 812. Additionally, the wedge shaped annularbody 812 comprises an exterior side surface 818 upwardly extending froma bottom annular end 820 to an underside 822 of an annular peripherallip 824 that radially extends outwardly and terminates to circumscribingouter edge surface 826 that transitions into a top planar annularsurface 828 radially extending between the central interior annularsurface 814 to the circumscribing outer edge surface 826. Further, thesqueeze ring 810 comprises the circumferentially spaced apart concavefaces or concavities 830 disposed in the exterior side surface 818 ofthe squeeze ring 810. As noted above, the curvature of each of thecircumferentially spaced apart concave faces or concavities 830 iscomplemental in shape to the arcuate shape of each of the plurality ofsegments or balls 742 for complemental arcuate surface abutmenttherebetween.

Still referring to FIGS. 49 and 50, the central opening 816 of theannular wedge or squeeze ring 810 is dimensioned to allow passage of theresilient annular body 812 between the balls 742 and annular spacer 738so as to allow a abutment and seating of the circumferentially spacedapart concave faces or concavities 830 of the annular wedge or squeezering 810 with the plurality of segments or spherical balls 742. In turn,and analogous to pipette tip coupler 100, the shank member 704 of thepipette tip coupler 700 is configured to operatively couple to thepipette device 20 of the pipette device assembly 10. With this coupling,the actuation of the squeeze motor 52 (FIG. 4) in the first directionresults in linear axial translation of the squeeze ring 810 in a distalor vertically downward direction for applying a force axially on the topsurface 828 of the squeeze ring 810 for forcing the concave faces orconcavities 830 to push uniformly against the arcuate surfaces ofplurality of spherical balls 742 for pushing them radially outwardly forcoupling with a disposable pipette tip such as disposable pipette tip220. Subsequent actuation of the squeeze motor 52 (FIG. 4) in a seconddirection, opposite the distal or vertically downward direction,releases the force on the squeeze ring 810 resulting in the plurality ofsegments or spherical balls 742 being urged back into the radial gap 740toward the annular spacer 738 thereby defining the retracted or tipdisengagement state of the plurality of balls 742.

Pipette Tip Coupler Device 900

Referring to FIGS. 51 and 52, a ball segment and seal pipette tipcoupler device 900 is illustrated that is an alternate exampleembodiment of the coupler device 100 for alternative use wherein thepipette tip coupler device 900 is configured to be coupled between, forexample, the disposable pipette tip 220 and the air displacement pipettedevice 20 of the air displacement pipette device assembly 10 (FIG. 1)utilizing the coupling process detailed above.

Referring to FIG. 51, the coupler device 900 comprises a centralcoupling member 902 comprising an elongated head or shank member 904, abody member 906, and distal stem portion 908. As illustrated, the shankmember 904 comprises a top end 910 and a lower end that transitions intoan upper surface 912 of the body member 906 and the body member 906comprises a lower end that transitions into the distal stem portion 908that terminates to a lower end 914 having a bottom end surface 916. Inone embodiment, the body member 906 has a diameter greater than adiameter of the shank member 904 and a diameter of the distal stemportion 908.

As also illustrated FIG. 51, the ball segment and seal pipette tipcoupler device 900 further comprises a distal elastomeric element 918circumscribing the distal stem portion 908 wherein the distalelastomeric element 918 is configured analogous to distal elastomericelement 160.

As further illustrated FIG. 51, the pipette tip coupler device 900further comprises a ball segment coupling system 920 disposed about theshank member 904 and mounted on body member 906, and the squeeze ring810 disposed about the shank member 904 and surmounting the ball segmentcoupling system 920.

Referring to FIG. 52, the ball segment coupling system 920 comprises araceway retainer body member 922, that is cylindrical in shape asillustrated in FIG. 53 and that comprises an annular base 924 having acentral opening 926 and an outer periphery transitioning into anupwardly extending circumscribing sidewall 928 having a plurality ofcircumferentially spaced apart circular holes 930 each defined by aninterior circumscribing cylindrical raceway surface 932 radiallyoutwardly transitioning into an interior annular tapering or conicsurface 934.

As illustrated in FIG. 52, the interior circumscribing cylindricalraceway surface 932 of each hole 930 has a first diameter 936 that islarger than the diameter of the ball segments 942. The interior annulartapering or conic surface 934 has a diameter that decreases from thefirst diameter 936 and terminates to a second diameter 935 that issmaller than the first diameter 936 and that is smaller than thediameter of each of the ball segments 942. Accordingly, the ballsegments 942 are retained by the interior annular tapering or conicsurfaces 934 from radially or horizontally moving out through therespective holes 930 of the raceway retainer body member 922 when in theradially translated state as illustrated in FIG. 51 thereby defining aball segment retention configuration that is machined into the racewayretainer body member 922 and that is an alternative to the abovedelineated retention configurations that comprise the retaining stakes406 illustrated in FIG. 36, the ball keeper retaining ring 506illustrated in FIG. 40, and the snap ring 744 illustrated in FIG. 48.

As illustrated in FIG. 51, the pipette tip coupler device 900 furthercomprises an annular spacer 938 disposed about shank member 904 andmounted on an inner upper surface 952 of the annular base 924 of theraceway retainer body member 922. The annular spacer 938 is dimensionedto define a radial gap 940 between the annular spacer 938 and the holes930 of the raceway retainer body member 922.

Referring to FIGS. 53 through 55, and during one example assemblyprocess, the plurality of cylindrical ball segments 942 are respectivelyreceived through the interior ends of the holes 930 (FIG. 52) of theupwardly extending circumscribing sidewall 928 (FIG. 52) of the racewayretainer body member 922. Next, the raceway retainer body member 922 isaligned with and mounted on the upper surface 912 of the body member 906of the central coupling member 902 wherein the raceway retainer bodymember 922 comprises a distally facing axial stop shoulder surface 950having a diameter greater than the diameter of the body member 906 asillustrated in FIG. 51. The stop shoulder surface 950 is functionallyanalogous to stop shoulder surface 134 (FIG. 6) of the coupler device100. The annular spacer 938 is then aligned with and mounted on theupper surface 912 of the body member 906 of the central coupling member902 within the cylindrically shaped raceway retainer body member 922.

Accordingly, and referring to FIG. 56, the plurality of cylindrical ballsegments 942 are respectively received within the holes 930 (FIG. 52)and are captured for radial movement while being precluded from escapingtherethrough by the interior annular tapering or conic surface 934 andback out by annular spacer 938.

As further illustrated in FIG. 51, the central coupling member 902comprises an open ended, interior cylindrical channel surface 954 thatdefines an open ended cylindrically shaped central channel 956 that runsalong the longitudinal central axis 958 of the pipette tip couplerdevice 900 from the annular proximal or top end 910 defining theproximal end face of the pipette tip coupler device 900 to the bottomend surface 916 defining the distal end face of the pipette tip couplerdevice 900. The open ended cylindrically shaped central channel 956provides open communication between the aspirating and dispensingcylinder 34 (FIG. 3) and, for example, the pipette tip 220 wherein theaspirating and dispensing cylinder 34 is also in open communication withthe aspirating and dispensing plunger 26 (FIG. 3).

Ball Coupling System Aspects

In one aspect, the ball coupling system comprises components that areformed from hard and durable materials such as, but not limited to,metallic or hard plastic to provide improved system life. And, becausethe balls are much harder than the plastic tip, they work into the tipgroove more efficiently than soft elastomeric material such as anO-ring.

In another aspect, the ball coupling system provides a much stifferjoint between the tip and the stop disk and, in particular, the rigidityof the plurality of discrete balls provides a more rigid coupling forproviding a stiffer joint between the pipette tip and pipette tipcoupler.

In another aspect, the ball coupling system pulls the tip up and seatsit more efficiently.

In another aspect, the life of the balls of the ball coupling systemwill not be affected by ejecting the tip in free air. In contrast,O-ring coupling life is adversely affected when the tip is ejected infree air because the O-ring is scuffed and abraded by the groove in thetip as the tip is pushed off by the spring loaded eject sleeve. Thehardness of the balls resists harmful acts of the scuffing and abrasion.

In another aspect, the ball coupling materials can easily be made fromconductive material in order to provide an electrical circuit to the tipfor liquid level detection or other uses.

In another aspect, ball coupling system can be activated with a lowsqueeze/axial force because of efficient mechanical design. A lowersqueeze/axial force requirement improves the life on the associatedparts providing the axial force. In another aspect, ball coupling systemallows the lower seal to have improved life span because of the lowersqueeze/axial force requirement noted above.

In another aspect, the distal seal can be made from a greater variety ofmaterials because it does not need to be conductive.

In another aspect, maintenance costs are lower because of the improvedlife and easier accessibility to the lower seal.

In another aspect, tip alignment to the pipette device is improvedbecause of improved seating.

Pipette Tip Coupler 1100

FIG. 57 illustrates a segment and seal pipette tip coupler device 1100that is an alternate example embodiment of the coupler device 100 andthat is illustrated interposed between the example embodiment of thedisposable pipette tip 220 and the example embodiment air displacementpipette device 20 of the air displacement pipette device assembly 10.

As illustrated in FIGS. 57 and 58, the pipette tip coupler 1100comprises an elongated head or shank member 1102, a pipette tip couplerbody 1120; a discrete element or segment coupling system 1160 comprisinga plurality of elements or segments defining a segment ring 1162 and aspring retainer 1172; a distal elastomeric element 1180; and an annularwedge or squeeze ring 1200 surmounting the plurality of elements orsegments 1162.

As illustrated in FIGS. 58 and 59, the elongated head or shank member1102 surmounts the pipette tip coupler body member 1120 and theplurality of elements or segments 1162 are circumferentially spacedapart and carried about the shank member 1102 on an upper annularsurface 1122 of a first cylindrical portion 1130 of the pipette tipcoupler body 1120. The spring retainer 1172 constrains the radialextension or circumferential increase of the plurality ofcircumferentially spaced apart elements or segments 1162.

Additionally, the pipette tip coupler 1100 comprises a lower or distalelastomeric element 1180 carried at a distal or lower end portion of thepipette tip coupler body 1120 as detailed below.

Furthermore, and as illustrated in FIGS. 64 and 65, the pipette tipcoupler 1100 comprises an annular wedge or squeeze ring 1200 surmountingthe plurality of elements or segments 1162 retained by spring retainer1172 such that the plurality of elements or segments 1162 are interposedbetween pipette tip coupler body 1120 and annular wedge 1200 wherein theplurality of elements or segments 1162 are radially moveable againstspring retainer 1172 between a radially retracted position and aradially extended position as a function of the axial location ofannular wedge 1200 as illustrated in FIGS. 66 through 70 by anincreasing gap 1174 (FIG. 68) between the interior annular surface 1282of each of the plurality of elements or segments 1162 and the ring 1116adjacently surmounting upper annular surface 1122 (FIG. 59).

Shank Member 1102

More specifically, and as illustrated in FIG. 59, the shank member 1102comprises an annular proximal end face 1104 defining a proximal or upperend face of the pipette tip coupler 1100 and comprising an outerperiphery 1106 that can be chamfered and that transitions into elongatedtubular body 1108.

Distal from proximal end face 1104, the elongated tubular body 1108transitions into an annular tapered portion 1110 that decreases indiameter and transitions into a cylindrical neck portion 1112. Thecylindrical neck portion 1112 distally transitions into a cylindricalcollar 1114 that has a diameter greater than a diameter of thecylindrical neck portion 1112. Next, the cylindrical collar 1114 isdistally followed by a ring 1116 that has a diameter greater than adiameter of the cylindrical collar 1114 and that surmounts an innerportion of the upper circular body end surface 1122.

As illustrated in FIG. 65, the shank member 1102 of the pipette tipcoupler 1100 is configured to fit within the distal mounting flange 36of the aspirating and dispensing cylinder 34 for operatively couplingthe pipette tip coupler 1100 to the pipette device 20 of the pipettedevice assembly 10.

Coupler Body 1120

As illustrated in FIG. 59, the superior or upper end surface 1122 of thepipette tip coupler body 1120 radially outwardly extends from the ring1116 and transitions into an outer peripheral edge 1124 that is rounded.In one example embodiment, the upper circular body end surface 1122 is asubstantially planar radially outwardly extending surface that extendsfrom the distal end of the ring 1116 to the outer peripheral edge 1124.

Additionally, the pipette tip coupler body 1120 comprises a multicylindrical section comprising a first cylindrical portion or stop diskportion 1130 that distally extends axially away from the upper endsurface 1122 and that is distally followed by a second cylindricalportion 1132 that is reduced in diameter for forming a distally ordownwardly facing axial shoulder surface or stop shoulder surface 1134between the adjoining first and second cylindrical portions 1130, 1132.

As illustrated in FIG. 59, the second cylindrical portion 1132 distallyextends from the stop shoulder surface 1134 to a distally facing lowersurface 1136 that radially inwardly transitions into a reduced diameterdistal cylindrical stem portion 1138 that terminates to a radiallyoutwardly extending upper surface 1140 of a generally round end plate1142. End plate 1142 comprises a rounded peripheral edge that provides acircumferential rounded transition between the upper surface 1140 of theend plate 1142 and a lower generally planar surface 1144 (FIG. 58) ofthe end plate 1142 defining the distal end face of the pipette tipcoupler body 1120 of pipette tip coupler 1100.

As illustrated in FIGS. 58 and 59, the first cylindrical portion 1130comprises a first diameter that is greater than a second diameter of thesecond cylindrical portion 1132 for forming the distally or downwardlyfacing axial shoulder surface or stop shoulder surface 1134 between thefirst and second cylindrical portions 1130, 1132. Additionally, thesecond diameter of the second cylindrical portion 1132 is greater than adiameter of the end plate 1142. Furthermore, a diameter of the distalcylindrical stem portion 1138 is less than both the second diameter ofthe second cylindrical portion 1132 and the diameter of the end plate1142 for defining a lower, distal groove 1148 between the secondcylindrical portion 1132 and the end plate 1142.

In one example embodiment, the first and second cylindrical headportions 1130 and 1132 respectively comprise generally smooth exteriorcylindrical surfaces and the distal cylindrical stem portion 1138comprises a generally smooth exterior cylindrical surface or groovesurface.

Referring to FIGS. 58 and 65, the pipette tip coupler 1100 furthercomprises an open ended, interior cylindrical channel surface 1156 thatdefines an open ended cylindrically shaped central channel 1158 thatruns along a longitudinal central axis 1198 of the pipette tip coupler1100 from the annular proximal end face 1104 defining the proximal endface of the pipette tip coupler 1100 to the lower generally planarsurface 1144 of end plate 1142 (FIG. 59) defining the distal end face ofthe pipette tip coupler 1100. The open ended cylindrically shapedcentral channel 1158 provides open communication between the aspiratingand dispensing cylinder 34 (FIG. 3) and the pipette tip 220 wherein theaspirating and dispensing cylinder 34 is also in open communication withthe aspirating and dispensing plunger 26 (FIG. 3).

Distal Elastomeric Element 1180

As illustrated in FIG. 60, the elastomeric element 1180 comprises anannular body 1182 having an interior surface 1184 defining a centralopening 1186, a top surface 1188, a peripheral exterior surface 1190,and a bottom surface 1192.

Referring to FIGS. 58 through 60, the central opening 1186 of the lowerelastomeric element 1180 is dimensioned to tightly circumscribe thedistal cylindrical stem portion 1138 of the pipette tip coupler 1100between the distally facing lower surface 1136 of the second cylindricalportion 1132 and the upper surface 1140 of the end plate 1142 of thepipette tip coupler body member 1120 wherein the surfaces 1136,1140 arein the form of, but not limited to, a planar, conical or concavedconfiguration.

Accordingly, as illustrated in FIG. 58, the lower or distal elastomericelement 1180 is carried at the lower or distal end portion of couplerbody 1120 by way of stem portion 1138 (FIG. 59) and is distal to thediscrete element or segment coupling system 1160 that is carried at theupper or proximate end portion of coupler body 1120. In a relaxed orunsqueezed state, the lower or distal elastomeric element 1180 comprisesa circumferentially continuous, generally circular cross section area1194 as is illustrated in FIG. 65.

Discrete Element or Segment Coupling System 1160

FIG. 61 illustrates an exploded parts view of the discrete element orsegment coupling system 1160 comprising the plurality of discreteelements or segments 1162 and the spring retainer 1172 having a gap 1174that allows circumferential expansion of segments 1162. The plurality ofdiscrete elements or segments 1162 define a segmented ring comprising,but not limited to, four discrete arcuate elements or segments 1164,1166, 1168, and 1170. The gapped spring retainer 1172 circumscribes thefour arcuate elements or segments 1164, 1166, 1168, and 1170 to form aradially extendable segmented ring comprising an annular base defined bythe bases 1278 (FIG. 62) of the plurality of discrete elements orsegments 1162 of discrete element or segment coupling system 1160.

Accordingly, and referring to FIG. 58, the discrete element or segmentcoupling system 1160, disposed on the upper surface 1122 of the firstcylindrical portion 1130 of the pipette tip coupler body member 1120(FIG. 59), retains the plurality of discrete elements or segments 1162and allows movement of the discrete elements or segments 1162 between arelaxed (FIG. 66) and an extended (FIG. 70) position.

Discrete Elements or Segments 1162

Referring to FIGS. 62 and 63, and in one example embodiment, each of theplurality of elements or segments 1162 comprises a resilient arcuateshaped body 1260 having a generally C-shaped continuous cross sectionalarea 1262 along an arcuate length of the arcuate shaped body 1260.

The arcuate shaped body 1260 comprises an upper arcuate sector 1264, amedial sector 1266, and a lower base sector 1268 having an exterior basesurface 1278. The upper arcuate sector 1264 comprises a top planarannular surface 1270 having an interior arcuate edge that transitionsinto a back side sloped surface 1272 of the body 1260 and having anouter front arcuate edge that transitions into a downwardly roundedperipheral arcuate edge sector 1274 (FIG. 63) that, in turn, transitionsinto a cutout surface 1276 of body 1260 forming a groove 1280. As FIG.62 illustrates, the cutout surface 1276 (FIG. 63) of body 1260, andtherefore groove 1280 (FIG. 62), has a shape, such as a generallyC-shaped or a sideways U-shaped configuration, for receipt of the springretainer 1172 (FIG. 61) that is not continuous in circumference, butincludes the gap 1174 for allowing expansion.

Additionally, each of the plurality of elements or segments 1162comprises an interior arcuate base surface 1282 extending between aninner edge of base surface 1278 and a bottom edge of the back sidesloped surface 1272 of the body 1260. Thus, in the discrete element orsegment coupling system 1160, the interior arcuate base surfaces 1282 ofthe plurality of segmented elements 1162 defines a central annular baseopening extending through the segmented coupling system 1160 surmountedby a central conical opening extending through the discrete element orsegment coupling system 1160 defined by the back side sloped surfaces1272 of the plurality of elements or segments 1162 of the discreteelement or segment coupling system 1160.

Annular Wedge or Squeeze Ring 1200

Referring to FIGS. 64 and 65, the annular wedge or squeeze ring 1200comprises a resilient wedge shaped annular body 1202 having acircumferentially continuous, generally wedge shaped cross section 1204as illustrated in FIG. 65. The resilient wedge shaped annular body 1202comprises a central interior annular surface 1206 defining a centralannular opening 1208 extending through the annular body 1202. Body 1202further comprises a top planar circular surface 1210 radially outwardlyextending from the central interior annular surface 1206 to acircumscribing outer edge surface 1212. A radially outwardly proximallyinclined side surface 1214 extends from a bottom annular end 1216 to anunderside of an annular peripheral lip 1218 that radially outwardlyextends and terminates to the circumscribing outer edge surface 1212.

The central annular opening 1208 of the wedge shaped annular body 1202is dimensioned to allow passage of the shank member 1102 so as to allowa seating abutment of radially outwardly proximally inclined sidesurface 1214 of the annular wedge squeeze ring 1200 with the pluralityof discrete elements or segments 1162 of the discrete element or segmentcoupling system 1160 carried on the upper end surface 1122 of thepipette tip coupler body 1120 of the pipette tip coupler 1100.

With the pipette tip coupler 1100 fitted within the distal mountingflange 36, the top planar circular surface 1210 of the annular wedge orsqueeze ring 1200 is adjacent the distal end 50 of the squeeze sleeve46. Accordingly, actuation of the squeeze motor 52 (FIG. 1) in the firstdirection results in linear axial translation of the squeeze sleeve 46in a distal or vertically downward direction for applying a forceaxially on the top surface 1210 of the annular wedge ring 1200 via theLLD circuit ring end 366 for forcing the inclined side surface 1214 topush against the plurality of discrete elements or segments 1162 forpushing them radially outward into the groove 246 of the tip 220 andinto contact with surface 244 (FIG. 16) as exemplified in FIGS. 64 and65. Subsequent actuation of the squeeze motor 52 (FIG. 1) in a seconddirection, opposite the distal or vertically downward direction, returnsthe distal end 50 of the squeeze sleeve 46 to a home position releasingthe applied force on the top surface 1210 of the annular wedge ring1200.

Discrete Element/Segment Coupling System Aspects

In one aspect, the discrete element or segment coupling system 1160comprises components that are formed from hard and durable materialssuch as, but not limited to, metallic or hard plastic to provideimproved system life and because the discrete elements or segments aremuch harder than the plastic tip, they work into the tip groove moreefficiently than soft elastomeric material such as an O-ring.

In another aspect, the discrete element or segment coupling system 1160provides a stiff joint between the tip and the stop disc.

In another aspect, the discrete element or segment coupling system 1160pulls the tip up and seats it efficiently.

In another aspect, the discrete element or segment coupling system 1160will not be affected by ejecting the tip in free air. The O-ringcoupling life is adversely affected when the tip is ejected in free airbecause the O-ring is scuffed and abraded by the groove in the tip asthe tip is pushed off by the spring loaded eject sleeve. The hardness ofthe discrete elements or segments resists the harmful acts of thescuffing and abrasion.

In another aspect, the materials of the discrete elements or segmentscan easily be made from conductive material in order to provide anelectrical circuit to the tip for liquid level detection or other uses.

In another aspect, the discrete element or segment coupling system 1160can be activated with a low squeeze/axial force because the mechanicaldesign is efficient. A lower squeeze/axial force requirement improvesthe life on the associated parts providing the axial force. As a resultof this lower squeeze/axial force requirement, the coupling system 1160allows the lower or distal seal to have improved life span because theelastomeric material is not compressed as much.

In another aspect, the coupling system 1160 allows the lower or distalseal to be easily accessed if replacement is required. Also, the loweror distal seal can be made from a greater variety of materials becauseit does not need to be conductive.

In another aspect, maintenance costs are lower because of the improvedlife and easier accessibility to the lower or distal seal.

In another aspect, tip alignment to the pipette device 20 is improvedbecause of improved seating.

Pipette Tip Pickup Process with Pipette Tip Coupler 1100

FIGS. 65 through 72 illustrate details of an example embodiment ofsuccessive stages of a pipette tip pickup process and, in particular, amethod of securing attachment of the pipette tip 220 to the pipette tipcoupler 1100 operatively carried by the pipette device 20. As notedabove, and in one example embodiment, the pipette tip 220 may besupported by a support surface 282 (FIG. 15).

As illustrated in FIG. 65, the pipette tip coupler 1100 is connected tothe pipette device 20, and upon command, the pipette tip coupler 1100 ispositioned over the open proximal end 232 of pipette tip 220 whereineach of their respective central longitudinal axes is aligned along theZ-axis. The eject sleeve 62 is in the eject position, the squeeze sleeve46 is in the unsqueezed position, the discrete element or segmentcoupling system 1160 is in the relaxed state, and the distal elastomericelement 1180 is in the unsqueezed state.

Next, FIG. 66 illustrates the pipette tip coupler 1100 being moved downalong the Z-axis into the pipette tip 220 for lowering the distal,elastomeric carrying portion of the pipette tip coupler 1100 into theinterior cylindrical proximal or upper end portions of the pipette tip220 to bring the distal O-ring 1180 into contact with the tip annularsealing seat or stop surface 270 while maintaining the plurality ofdiscrete elements or segments 1162 in the unextended or unsqueezed stateand before the proximally or upwardly facing annular shoulder seat orstop surface 260 of the pipette tip 220 and the distally of downwardlyfacing axial stop shoulder surface 1134 of the stop disk 1130 are matedsuch that a gap 298 is maintained between the annular shoulder seat orstop surface 260 of the pipette tip 220 and the axial stop shouldersurface 1134 of the stop disk 1130.

Next, FIG. 67 illustrates both the pipette tip coupler 1100 and squeezesleeve 46 being moved down along the Z-axis with the squeeze sleeve 46squeezing the annular wedge ring 1200 against the plurality of discreteelements or segments 1162 for starting the process of pulling the tip220 up and starting the process of pushing or squeezing the plurality ofdiscrete elements or segments 1162 radially outward and into the groove246. Specifically, the start of this pushing process initially placesthe downwardly rounded peripheral arcuate edge sector 1274 of each ofthe plurality of discrete elements or segments 1162 into abutment withthe upper axially arcuate circumferential surface sector portion 250 ofthe axially arcuate circumferential interior surface 244 defining thegroove 246 as illustrated in FIG. 68.

Referring to FIGS. 67 through 69, the action of the plurality ofdiscrete elements or segments 1162 extending or being projected into thegroove 246 into abutment with the upper axially arcuate circumferentialsurface sector portion 250 causes an axial upward force that pulls thepipette tip 220 up for starting a process of seating the annularshoulder seat surface 260 of the pipette tip 220 with the axial stopshoulder surface 1134 of the stop disk 1130 for closing the gap 298 andcompressing the distal O-ring 1180 with the sealing seat or stop surface270 of the tip 220 to start a process of energizing the distal O-ring1180 into a storage state of elastic potential energy to be released asa force from the O-ring 1180 to the sealing seat or stop surface 270 ofthe tip 220 during the tip 220 ejection process.

FIG. 70 illustrates the squeeze sleeve 46 being moved down along theZ-axis a pre-calibrated or predetermined length until it is locked inposition resulting in the annular wedge squeeze ring 1200 being stoppedand locked in position by the squeeze sleeve 46. As a result, theplurality of discrete elements or segments 1162 are radially extendedcircumferentially to a desired value (FIG. 71) for fully seating theaxial stop shoulder surface 1134 of the pipette tip coupler 1100 againstthe annular shoulder seat surface 260 (FIG. 16) of the pipette tip 220with the seating of the two surfaces 1134, 260 along an X-axissubstantially perpendicular to the Z-axis for forming a normal datumbetween the two axis while the distal O-ring 1180 is compressed to adesired value for seating the distal O-ring 1180 with the annularsealing seat or stop surface 270 of the tip 220 (FIG. 72) to finish theprocess of energizing the distal O-ring 1180 into the storage state ofelastic potential energy to be released as a force from the O-ring 1180to the sealing seat or stop surface 270 of the tip 220 during the tip220 ejection process.

Upon completion of the securing attachment process, the discrete elementor segment coupling system 1160 and the distal elastomeric element 1180work in combination to produce a segment and seal coupling that providesa fluid-tight seal wherein the plurality of discrete elements orsegments 1162 are at least partially received within the circumferentialgroove 246 and at least partially seated on the circumferential arcuateinterior surface 244 defining the circumferential groove 246 and whereinthe distal elastomeric element 1180 seals against the radially inwardlyangled and distally extending surface 270 of the pipette tip 220 in astorage state of elastic potential energy.

Ejection Process

Ejecting the pipette tip 220 from the pipette tip coupler 1100operatively carried by the pipette device 20 is similar to theattachment or tip pickup securing process sequence except in reverse andfollows the process as detailed above for ejecting the pipette tip 220from the pipette tip coupler 100. As also described above, the act ofuncompressing the distal elastomeric element 1180 provides a force fromthe released elastic potential energy of the compressed distalelastomeric element 1180 to provide a force to help remove the tip 220during the ejection process.

Coupling and Ejection Forces

FIG. 73 illustrates a vector diagram associated with the plurality ofdiscrete elements or segments 1162 of the pipette tip coupler 1100initially extending into the groove 246 with the plurality of discreteelements or segments 1162 contacting the upper corner of the tip grooveresulting in an axial upward force pulling the pipette tip 220 upward.As illustrated in FIG. 73, each segmented element force(Fsegment_resultant) is comprised of two components: an axial force(Fsegment_axial) component and a radial force (Fsegment_radial)component.

As long as the plurality of discrete elements or segments 1162 arecontacting the upper corner of the tip groove above the center of thesegment radius, dimension Z on FIG. 74, Fsegment_axial acts to pull thetip up toward the stop disk and increases as the distance between thecenter of the segment radius and the corner of the groove increases.Accordingly, at the beginning of the tip pickup process, thesegment_axial force (Fsegment_axial) starts out low as illustrated indetail in FIG. 74 and increases to its maximum at the end of the tippickup process as illustrated in FIG. 75.

Referring to FIG. 74, the ratio of Z/R equals SIN (w) and SIN (w) isequal to (Fsegment_axial)/(Fsegment_resultant). As a result,(Fsegment_axial) is equal to (Fsegment_resultant) multiplied by theratio of Z/R. From this, the result is that (Fsegment_axial) increasesas Z increases.

Referring to FIG. 75, the segment_axial force (F segment_axial) seatsthe stop disk 1130 against seat 260 of the tip 220 and provides theforce required to overcome an O-ring axial force and compress the O-ring1180. The segment_radial force (Fsegment_radial) provides the radialforce needed to lock the segment into the tip groove.

The O-ring 1180 has an O-ring force (Fdistal_ring_resultant) thatresults from being compressed and this force comprises two components:an axial component (Fdistal_ring_axial) and a radial component(Fdistal_ring_radial).

The segment_axial force (Fsegment_axial) provides the force to overcomethe O-ring axial force (Fdistal_ring_axial) and compress the O-ring1180. The segment to tip groove geometry that causes Fsegment_axial toincrease as the segment enters the groove (increasing dimension Z) helpsto overcome the O-ring axial force so that the O-ring can be completelycompressed to the desired extent.

Again, the segment_radial force (Fsegment_radial) provides the radialforce needed to lock the segment into the tip groove and the O-ringradial force component (Fdistal_ring_radial) provides the radial forceneeded to maintain the seal against the tip.

Furthermore, the O-ring axial force component (Fdistal_ring_axial)provides force to help remove the tip 220 during the ejection process.

Alignment/Misalignment

Analogous to coupler 100, the horizontal plane of the axial shouldersurface 1134 of coupler body member 1120 of the coupler 1100 and thehorizontal plane of the axial shoulder seat 260 of tip 220 aremaintained in a parallel adjacent relationship for correct tipalignment.

Dimensions and Relationships

Additionally, it is noted that for proper use and operation, dimensionsbetween the coupler 1100 and tip 220 are related accordingly asdescribed above for coupler 100.

Liquid Level Detection (LLD) Circuit Contacts

Referring to FIGS. 32 and 70, the pipette device assembly 10 furthercomprises a liquid level detection circuit assembly employed withpipette tip coupler 1100 in a manner analogous to coupler 100 describedhereinabove for having an ability to detect a surface of a liquid beingtransferred or a surface onto or from which liquid is being transferred.

As illustrated in FIG. 70, the ring end 366 of the LLD circuit contact364 is captured and sandwiched between the squeeze sleeve 46 and thesqueeze ring 1200 for making electrical contact between the processingcircuitry 362 of the LLD circuit board 360 (FIG. 32) and the squeezering 1200 that is made from an electrically conductive material and thatmakes electrical contact with the plurality of radially outwardlyprojecting segments 1162 that are also made using an electricallyconductive nonpliable material. Accordingly, with the tip attached andthe plurality of radially outwardly projecting segments 1162 squeezed orpushed and locked into the tip groove 246 (FIG. 71) of the tip 220, theplurality of radially outwardly projecting segments 1162 make electricalcontact with the tip 220 that is also made from an electricallyconductive material. As a result, and referring to FIG. 32, thiscompletes the circuit between the processing circuitry 362 of the LLDcircuit board 360 and the tip 220.

Additionally, the stop disk mounting post or distal mounting flange 36is made from a non-conducting material. Therefore, the shank member1102, body member 1120, and the plurality of radially outwardlyprojecting segments 1162 are insulated from the rest of the assembly.

Furthermore, the processing circuitry 362 of the LLD circuit board 360detects a signal change when the tip 220 contacts liquid thereby havingan ability to detect a surface of a liquid being transferred or asurface onto or from which liquid is being transferred. Again, actuationoccurs when the coupler 1100 is attached to the tip 220 and theplurality of radially outwardly projecting segments 1162 are radiallypushed circumferentially and locked into the tip groove of the tip 220.

Further Pipette Tip Embodiments

In a further embodiment, FIG. 76 illustrates a fragmentary, longitudinalsectional, side elevational view of the example embodiment of thedisposable pipette tip 220 comprising an alternative sealing seatsurface 2270 having an angle of substantially ninety degrees relative tothe central longitudinal axis of the pipette tip 220.

FIG. 77 illustrates the example embodiment of the disposable pipette tip220 comprising the alternative sealing seat surface 2270 being alignedfor mating with, for example, the pipette tip coupler device 100.

FIG. 78 illustrates the pipette tip coupler device 100 positioned in thedisposable pipette tip 220 comprising the alternative sealing seatsurface 2270 wherein the tip 220 with the alternative sealing seatsurface 2270 is lifted up to its final seated state and the annularwedge 210 moved into its final position for defining a final couplingstate with the distal elastomeric element 160 in a final compressed andseated sealing state against the alternative sealing seat surface 2270having the alternative sealing seat surface angle of substantiallyninety degrees.

FIG. 79 illustrates a detailed view of the distal elastomeric element160 in the final compressed state against the alternative sealing seatsurface 2270 having the alternative sealing seat surface angle ofsubstantially ninety degrees.

In a further embodiment, FIG. 80 illustrates a fragmentary, longitudinalsectional, side elevational view of the upper interior of the exampleembodiment of the disposable pipette tip comprising another alternativesealing seat surface in the form of a circumferential radially concavesealing seat surface 3270 that is further illustrated in detail in FIG.81.

In a further embodiment, FIG. 82 illustrates a fragmentary, longitudinalsectional, side elevational view of the example embodiment of thedisposable pipette tip illustrating detail of a further alternativesealing seat surface in the form of a circumferential radially convexsealing seat surface 4270 that is further illustrated in detail in FIG.83.

In a further embodiment, FIG. 84 illustrates a fragmentary, longitudinalsectional, side elevational view of the example embodiment of thedisposable pipette tip illustrating a yet further alternative sealingseat surface in the form of a circumferential upward facing tooth edgesealing seat surface 5270 that is further illustrated in detail in FIG.85.

FIG. 86 illustrates pipette tip coupler device 100 positioned over theexample embodiment of the disposable pipette tip 220 comprising analternative V-shaped groove 2246 defined by a V-shaped circumferentialinterior surface 2244 of the disposable pipette tip 220 opening towardthe longitudinal Z axis and having a V-shaped cross section asillustrated.

FIG. 87 illustrates the pipette tip coupler device 100 being positionedin the disposable pipette tip 220 comprising the alternative V-shapedgroove 2246 (FIG. 86) wherein the tip 220 with the alternative V-shapedgroove 2246 is lifted up to its final state with the rounded surfaces ofthe plurality of spherical balls 200 being extended into the V-shapedgroove 2246 and into abutment against the V-shaped circumferentialinterior surface 2244 with the distal elastomeric element 160 in thefinal compressed and seated sealing state against the sealing seatsurface 270 of the tip.

FIG. 88 illustrates the detail of the rounded surface of one of theplurality of segments or balls 200 being extended into the V-shapedgroove 2246 (FIG. 86) and abutting against the V-shaped circumferentialinterior surface 2244.

Furthermore, FIGS. 89 through 99 illustrate fragmentary, longitudinalsectional, side elevational views detailing further differentalternative example embodiments of the circumferential annular tipgroove 246 illustrated in FIG. 16.

In particular, FIGS. 89 through 99 illustrate respective grooveconfigurations 3001, 3002, 3003, 3004, 3005, 3006, 3007, 3008, 3009,3010, and 3011. Additionally, the segments of the couplers may compriseradially outwardly extending faces complementary to the respectivedifferent alternative example embodiments of the respective grooveconfigurations 3001 through 3011.

Moreover, the alternative sealing seat geometries 270 (FIG. 16), 2270(FIG. 76), 3270 (FIG. 80), 4270 (FIG. 82), and 5270 (FIG. 84) may beemployed with any one of the circumferential annular tip groovegeometries 2246 3001, 3002, 3003, 3004, 3005, 3006, 3007, 3008, 3009,3010, or 3011 respectively illustrated in FIGS. 89 through 99 andannular tip groove geometry 2246 illustrated in FIG. 860. Moreover, theelastomeric element may also have alternate shapes than an O-ring shapeand may be in the form of, but not limited to, configurationscomplementary to the tip sealing seat.

In another example embodiment, FIG. 100 details an interior of adisposable pipette tip 1220 that is analogous in all portions todisposable pipette tip 220 with the exception that interrupted interiorsurface section 242 is devoid of interruption thereby defininguninterrupted interior surface section 1242 of the disposable pipettetip 1220.

In alternative embodiments, the disposable pipette tip 1220 can alsoemploy one of the alternative sealing alternative sealing seatgeometries 270 (FIG. 16), 2270 (FIG. 76), 3270 (FIG. 80), 4270 (FIG.82), and 5270 (FIG. 84) detailed above.

FIG. 101 illustrates pipette tip coupler device 100 positioned over theexample embodiment of the disposable pipette tip 1220 comprisinguninterrupted interior surface section 1242.

FIG. 102 illustrates the pipette tip coupler device 100 positioned inthe disposable pipette tip 1220 with the stop shoulder surface 134 ofthe coupler device 100 abutting against the axial stop surface 260 ofdisposable pipette tip 1220 with the rounded surfaces of the pluralityof spherical balls 200 being extended against the interior surface 1242(FIG. 103) of the circumscribing sidewall of the disposable pipette tip1220 resulting in a deformation 1244 adjacent the interior surface 1242(FIG. 103) of the disposable pipette tip 1220 and with the distalelastomeric element 160 in the final compressed and seated sealing stateagainst the sealing seat surface 270 of the second example embodiment ofthe disposable pipette tip 1220.

Accordingly, the first working surface is in the form of, but notlimited to, the respective groove configurations or the uninterruptedconfiguration illustrated in FIGS. 100-103 wherein the firstsubstantially cylindrical interior surface section 242 is devoid ofinterruption thereby defining uninterrupted interior surface section1242 of the disposable pipette tip 1220.

Shoulder Seat Surface Comprising Axially Upwardly Projecting Rib 5020

In another example embodiment, FIGS. 104 and 105 detail an upperinterior of a disposable pipette tip 5000 that is analogous in allportions to disposable pipette tip 220 (FIG. 16) with the exception ofan alternative interior axially upwardly facing shoulder seat surfacehaving an axially upwardly facing annular groove 5010 coaxially disposedaround an axially upwardly extending circumscribing rib 5020 having acontinues solid circumscribing cross section.

As illustrated in FIGS. 104 and 105, the first substantially cylindricalinterior surface section 242 is axially distally proceeded by the secondsubstantially cylindrical interior surface section 262 having a seconddiameter less than the first diameter of the first substantiallycylindrical interior surface section 242 for forming the proximallyfacing, radially inwardly extending annular shoulder 5002 comprising theaxially upwardly facing annular groove 5010 coaxially disposed aroundthe axially upwardly extending circumscribing rib 5020.

In one embodiment, and as illustrated in FIG. 106, the axially upwardlyextending circumscribing rib 5020 comprises an uppermost rib seatsurface or rib apex 5022 transitioning into sloping rib side surfaces5024 and 5028. Sloping rib side surface 5024 transitions into an annularconvex surface 5026 that terminates to the second substantiallycylindrical interior surface section 262. On the outer radial side ofthe circumscribing rib 5020, sloping side surface 5028 forms a side wallsurface of a groove surface 5008 defining the groove 5010. The groovesurface 5008 further comprises a lower surface 5004 that transitionsbetween the side surface 5028 and a sloping side surface 5006 thattransitions into the first substantially cylindrical interior surfacesection 242.

In one embodiment, and referring to FIGS. 104 through 106, the axiallyupwardly extending circumscribing rib 5020 comprising the rib apex 5022may be formed by, for example, the removal of material from the uppersurface of the proximally facing, radially inwardly extending annularshoulder to form the groove 5010 or by the upper surface of theproximally facing, radially inwardly extending annular shoulder beingmolded to be devoid of material to form the groove 5010.

Referring to FIGS. 107 and 108, the disposable pipette tip 5000 can beused with one of the pipette tip coupler devices described above such ascoupling device 700 wherein reducing the proximally facing surface areaof the radially inwardly extending annular shoulder 5002 by forming ribapex 5022 provides an increase in the pressure between the tip 5000 andthe stop shoulder surface 750 of the coupling device 700 on the rib apex5022.

Referring to FIGS. 26, 107 and 108, the axial force (Fball_axial)produced by the ball 742 engaging the groove 250 will push against therib apex 5022 thereby producing a seal between the tip 5000 and surface750. Since pressure (P) is equal to force (F) divided by area (A),reducing the surface area of the tip seating shoulder by providing therib apex 5022 results in increased pressure (P=F/A). This increasedpressure between the tip 5000 and surface 750 provides a seal.Accordingly, the disposable pipette tip 5000 provides a new seal forevery use. In alternative embodiments, circumscribing rib 5020 may alsobe provided by a sealant bead, an elastomeric washer, an O-ring, orother material to provide a configuration exemplified by rib 5020.

Internal Seal Pipette Tip Assembly 6010

In another example embodiment, FIG. 109 illustrates an exampleembodiment of an internal seal pipette tip assembly 6010 comprising aninternal seal pipette tip 6020 and an internal seal 6030.

Referring to FIGS. 109 and 110, the pipette tip 6020 is analogous in allportions to disposable pipette tip 220 (FIG. 16) with the exception ofan alternative interior axially upwardly facing shoulder seat surfacehaving an axially upwardly facing annular groove 6040 coaxially disposedaround an axially upwardly extending circumscribing rib 6050 having anuppermost rib seat surface or rib apex 6052.

As illustrated in detail in FIG. 111, axially upwardly extendingcircumscribing rib 6050 comprises an uppermost rib seat surface or ribapex 6052 transitioning into an annular convex surface 6054 on theradially inner side of the rib apex 6052 and transitioning into a stepside surface 6056 on the radially outer side of the rib apex 6052.Convex surface 6054 transitions into the second substantiallycylindrical interior surface section 262 and step side surface 6056forms a side wall surface of a groove surface 6058 defining the groove6040. The groove surface 6058 further comprises a lower surface 6060that transitions between the side surface 6056 and an axially upwardlyextending side surface 6062 that transitions into the firstsubstantially cylindrical interior surface section 242.

As illustrated in FIG. 112, the internal seal 6030 is configured to bedisposed for compression in the axially upwardly facing annular groove6040 (FIG. 111) defined by groove surface 6058. Additionally, and asillustrated in FIG. 113, the internal seal 6030 is further configured tocomprise in its uncompressed state an axially upwardly extendingcircumscribing sector portion 6032 having an axial elevation greaterthan the axial elevation of the circumscribing rib apex 6052 of theaxially upwardly extending circumscribing rib 6050.

The internal seal pipette tip assembly 6010 can be used with any of thepipette tip coupler devices described above such as coupling device 700as is illustrated in FIGS. 114 and 115 wherein the pipette tip couplerdevice 700 is positioned in and operatively coupled to the internal sealpipette tip assembly 6010 (FIG. 109). With the pipette tip couplerdevice 700 operatively coupled to the internal seal pipette tip assembly6010 as is illustrated in FIGS. 114 and 115, the distally facing axialstop shoulder surface 750 of the third example embodiment of the pipettetip coupler device 700 compresses the internal seal 6030 disposed in theaxially upwardly facing annular groove 6040 to the extent of contactbetween the distally facing axial stop shoulder surface 750 and the ribapex 6052 of the axially upwardly extending circumscribing rib 6050(FIG. 111). Once the tip assembly 6010 and the coupling device 700 areoperatively coupled together, the internal seal 6030 provides a sealbetween the tip 6020 and the coupling device 700.

Accordingly, the internal seal pipette tip assembly 6010 provides a newinternal seal 6030 for every use. Additionally, the internal seal 6030provides a secondary sealing function and, in one embodiment, areplacement seal for distal seal 718. In one embodiment, the internalseal 6030 may be molded in place during the molding operation of the tip6020. In other example embodiments, the internal seal 6030 may compriseanother sealing mechanism, such as elastomeric element such as anO-ring, elastomeric washer, a thin layer of sealant, a sealant bead, anadhesive, or other sealant material or mechanism

A Further Aspect

In light of the above, and in a further aspect, an example embodiment ofa method is provided for securing attachment of at least one pipette tipto at least one pipette tip coupler carried by a pipette device; themethod comprising: (1) providing a pipette tip coupler comprising anupper body portion carrying a plurality of circumferentially disposedsegments, a lower stem portion carrying an elastomeric sealing element,and a axially downwardly facing axial stop surface located axiallybetween the plurality of circumferentially disposed segments and theelastomeric sealing element, the pipette tip coupler further comprisingan interior circumscribing sidewall defining a central channel extendingalong a longitudinal central axis of the pipette tip coupler; (2)providing a pipette tip comprising a sidewall having an interiorcircumscribing surface defining a passage opening extending between anopen distal end intended for immersion in a medium to be pipetted and anopen proximal end opposite in an axial direction to the open distal endand the pipette tip comprising an upwardly facing axial stop surfaceformed by an axially stepped shoulder of the interior circumscribingsurface of the sidewall of the pipette tip; (3) translating the pipettetip coupler through the open proximal end of the pipette tip leadingwith the lower stem portion; and (4) moving the plurality ofcircumferentially disposed segments between a radially retracted stateand a radially translated state circumferentially for abutting an outerportion of the plurality of circumferentially disposed segments with afirst interior working surface of the interior circumscribing surface ofthe sidewall of the pipette tip at a location axially above the upwardlyfacing axial stop of the pipette tip for lifting the pipette tip to abutthe upwardly facing axial stop shoulder surface of the pipette tip withthe distally facing axial stop shoulder surface of the upper bodyportion of the pipette tip coupler while concurrently compressing theelastomeric element against a second interior working surface of theinterior circumscribing surface of the sidewall of the pipette tip at alocation axially below the upwardly facing axial stop shoulder surfaceof the pipette tip.

INDUSTRIAL APPLICABILITY

The above delineation of the systems, assemblies, devices, and methodsincluding uses and operations, demonstrate the industrial applicabilityof embodiment(s) of the present disclosure.

In light of the present disclosure as set forth above, it should beapparent that further numerous structural modifications and adaptationsmay be resorted to without departing from the scope and fair meaning ofthe embodiment(s) of the present disclosure as set forth hereinabove andas described hereinbelow by the claims. Hence, the spirit and scope ofthe appended claims should not be limited to the above delineateddescription of the embodiment(s) of the present disclosure. And, in theappended claims reference to an element in the singular is not intendedto mean “one and only one” unless explicitly so stated, but rather “oneor more.” Moreover, it is not necessary for a device or method toaddress each and every problem sought to be solved by the presentdisclosure, for it to be encompassed by the present claims.

What is claimed is: 1- A method for securing attachment of a pipette tipto a pipette tip coupling device carried by a pipette device, the methodcomprising: providing a pipette tip coupler coupled to a pipette device,the pipette tip coupler comprising: a shank; a coupler body distal tothe shank; a distal stem portion; a distal end plate; an open-endedinterior circumscribing surface forming an open passageway extendinglongitudinally from the proximal end face through the distal end plate;an elastomeric element disposed around the distal stem portion andadjacent to the distal end plate; and a pipette tip ball assemblycircumscribing the shank comprising: a plurality of spherical balls; anda ring-shaped raceway body comprising: a plurality of circumferentiallyspaced apart guide sockets for carrying the plurality of sphericalballs; and a plurality of circumferentially spaced apart circular ballopenings for receiving and retaining the plurality of spherical balls;and an annular wedge; providing a pipette tip comprising acircumscribing sidewall with an open interior passage including aninterior surface and extending along a central longitudinal axis of thepipette tip between an open proximal end and an open distal end of thepipette tip; locating the pipette tip coupling device over the openproximal end of the pipette tip with an axial alignment between acentral longitudinal axis of the pipette tip coupler and the centrallongitudinal axis of the pipette tip; inserting the pipette tip couplerthrough the open proximal end of the pipette tip leading with the distalend plate of the pipette tip coupler; and applying a mechanical forceagainst the annular wedge to push each of the plurality of sphericalballs radially outward along one of the plurality of circumferentiallyspaced apart guide sockets to abut the plurality of spherical ballsagainst a first portion of the interior surface of the circumscribingsidewall of the pipette tip for securing the pipette tip to the pipettetip coupling device and to abut the elastomeric element against a secondportion of the interior surface of the circumscribing sidewall of thepipette tip to form a seal between the pipette tip coupling device andthe pipette tip.